Intra-RAT handovers with core network change

ABSTRACT

Methods and apparatus are provided for handover of a UE from a source node connected to a first core network to a target node connected to a second core network. The UE receives, from the source node, a mobility command including an indication of the radio access technology (RAT) used by the target node and a message container containing configuration information for the target node. The UE further determines, based on the indication of the RAT used by the target node, whether to treat the handover as an inter-RAT handover or as an intra-RAT handover with a core network change, and performs a radio resource control procedure for one of an inter-RAT handover or an intra-RAT handover with a core network change based on the determination.

RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 16/326,887, which was filed on Feb. 20, 2019, which is anational stage application of PCT/EP2019/051327, which was filed on Jan.21, 2019, and claims benefit of U.S. Provisional Application 62/653,526,which was filed Apr. 5, 2018, the disclosures of each of which areincorporated herein by reference in their entirety.

TECHNICAL FIELD

The present disclosure relates generally to handover procedures forwireless communication networks and, more particularly to handoverprocedures for handovers between base stations connected to differentcore networks.

BACKGROUND

Evolved Universal Terrestrial Radio Access (E-UTRA) is the air interfaceused in the Third Generation Partnership Project (3GPP) standard knownas Long Term Evolution (LTE). The base stations in LTE networks aregenerally known as Evolved NodeBs (eNBs). Intra-Radio Access Technology(RAT) handover in LTE between eNBs without Core Network (CN) change isperformed with a RRCConnectionReconfiguration message including themobilityControlInfo Information Element (IE), generated by the targetEvolved NodeB (eNB) and delivered to the user equipment (UE) by thesource eNB. For a successful reconfiguration, the UE responds with aRRCConnectionReconfigurationComplete message.

Inter-RAT handover from LTE basically implies to a full configuration ofthe UE, where none of LTE-established protocol sublayers and previouslyused security keys are kept. A tunneling procedure is adopted, where thesource eNB sends a MobilityFromEUTRACommand message to the UE containingan embedded message pertinent to the target RAT. TheMobilityFromEUTRACommand message contains a targetRAT-MessageContainerand TargetRAT-type indication. The former contains the configurationmessage itself from the target RAT and the latter defines the RAT, e.g.,UTRA, GERAN. The nas-SecurityParamFromEUTRA is used for security keyderivation in UTRAN.

Similarly, inter-RAT handover to LTE is performed in a tunneling schemewith the RRCConnectionReconfiguration message delivered to the UE viathe source RAT. This Radio Resource Control (RRC) message indicates afull configuration and does not retain any protocol sublayersestablished by the source RAT and previously derived security keys.

When moving from E-UTRA, specific actions are taken for successful andfailure handover case, as specified in sections 5.4.3.4 and 5.4.3.5respectively, from 3GPP TS 36.331 (v15.0.1 [2018-01]). For thesuccessful handover cases, the procedure triggers the release of allE-UTRA configurations established. When moving to E-UTRA, specificactions are taken for failure handover case, as specified in section5.4.2.5, from 3GPP TS 36.331 (v15.0.1 [2018-01]).

There currently exist certain challenges for supporting intra-RAThandover with a core network change. In legacy inter-RAT handover inE-UTRA, when making a successful handover from E-UTRA, all theconfigurations are released from E-UTRA since the UE would be connectedto a different target RAT. However, since the same procedures would beused for handover case of intra-LTE with CN change, the release ofE-UTRA configuration after completing the MobilityFromEUTRACommandprocedure will force the UE transitions to IDLE mode returning toCONNECTED mode in the new node that is attached to a different CN.

The same rationale is applied for failure cases in current proceduresfor inter-RAT handover in E-UTRA. That is, when mobility from E-UTRA orhandover to E-UTRA fails, a connection re-establishment procedure isperformed and thus the UE transitions to IDLE mode before returning toCONNECTED mode with the node (or another node) that is attached to theoriginal CN. Also, multiple failure procedures could be initiatedbecause there are failure procedures for handover from and to E-UTRA, aswell as failure during reception of RRCConnectionReconfigurationmessage, with different actions taken in each case.

SUMMARY

Certain aspects of the present disclosure and their embodiments mayprovide solutions to these or other challenges. For intra-RAT handoverwith CN change, the source node and target node implement signalingprocedures similar to the case where inter-RAT handover is performed,but the procedures invoked for success or failure of the handover aresimilar to the case for an intra-RAT handover. Enhancements to the RRCinter-RAT mobility procedures are made whereby the legacy behavior ofleaving the original RAT (upon the successful completion) or there-establishment (in case of failure) are prevented.

According to one aspect of the disclosure, methods and apparatus areprovided to handle failure while trying to perform E-UTRA inter-RAThandover after receiving a handover command with RRC (connection)reconfiguration message, to include actions specific for the case ofE-UTRA intra-RAT handover with CN change. Since the case combines threedifferent procedures; Mobility from E-UTRA, handover to E-UTRA andRRCConnectionReconfiguration, which all trigger a failure upon theexpiration of the timer T304. This problem is avoided by the methods andapparatus herein described.

According to one aspect of the disclosure, methods and apparatus areprovided to handle successful handover in E-UTRA inter-RAT case, afterreceiving a handover command with RRC (connection) reconfigurationmessage, to include actions specific for the case of E-UTRA intra-RAThandover with CN change. Since a successful handoverMobilityFromEUTRACommand procedure would result in the UE releasing allradio resources, which problem is avoided by the methods and apparatusherein described.

An advantage of the solution is that intra-RAT handover with CN changecan be performed with proper functioning of successful and failurecases, which will prevent ambiguity in the performed actions in RadioResource Control (RRC). Without the changes proposed in this disclosure,a UE will be forced to go via the IDLE mode when performing an intra-LTEinter-system handover, which could cause a major service disruption(e.g., if the UE already has active delay sensitive services/bearers).

Some embodiments of the disclosure comprise methods implemented by a UEin a wireless communication network of performing a handover from asource node connected to a first core network to a target node connectedto a second core network. The UE receives, from the source node, amobility command including an indication of the radio access technology(RAT) used by the target node and a message container containingconfiguration information for the target node. The UE furtherdetermines, based on the indication of the RAT used by the target node,whether to treat the handover as an inter-RAT handover or as anintra-RAT handover with a core network change, and performs a radioresource control procedure for one of an inter-RAT handover or anintra-RAT handover with a core network change based on thedetermination.

Other embodiments of the disclosure comprise a UE configured to performthe above described method. In one embodiment, the UE comprises acommunication circuit configured for communication with one or morenodes in the wireless communication network and a processing circuit.The processing circuit is configured to receive, from a source node, amobility command including an indication of the radio access technology(RAT) used by a target node, and a message container containingconfiguration information for the target node. The processing circuit isfurther configured to determine, based on the indication of the RAT usedby the target node, whether to treat the handover as an inter-RAThandover or as an intra-RAT handover with a core network change, and toperform a radio resource control procedure for one of an inter-RAThandover or an intra-RAT handover with a core network change based onthe determination.

Another aspect of the disclosure comprises computer programs forconfiguring a UE to perform the above described methods. The computerprogram comprises instructions that, when executed on at least oneprocessor of a UE cause the UE to perform the method described above. Acomputer program in this regard may comprise one or more code modulescorresponding to the means or units described above.

Embodiments further include a carrier containing such a computerprogram. This carrier may comprise one of an electronic signal, opticalsignal, radio signal, or non-transitory computer readable storagemedium.

Other embodiments of the disclosure comprise methods performed by a basestation. The base station sends, to a UE, a mobility command including aradio access technology (RAT) type indication and a message containercontaining configuration information for the target node. The basestation sets the RAT type indication in the mobility command to apredetermined value to indicate to the user equipment that the handoverinvolves a core network change.

Other embodiments of the disclosure comprise a base station configuredto perform the above described method. In one embodiment, the basestation comprises a communication circuit configured for communicationwith the UE and a processing circuit. The processing circuit isconfigured to send, to the UE, a mobility command including a radioaccess technology (RAT) type indication and a message containercontaining configuration information for the target node. The processingcircuit is further configured to set the RAT type indication in themobility command to a predetermined value to indicate to the userequipment that the handover involves a core network change.

Another aspect of the disclosure comprises a computer program forconfiguring a base station to perform the above described methods. Thecomputer program comprises instructions that, when executed on at leastone processor of a base station cause the base station to perform themethod described above. A computer program in this regard may compriseone or more code modules corresponding to the means or units describedabove.

Embodiments further include a carrier containing such a computerprogram. This carrier may comprise one of an electronic signal, opticalsignal, radio signal, or non-transitory computer readable storagemedium.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a successful RRC connection reconfiguration followingan intra-LTE handover.

FIG. 2 illustrates a successful inter-RAT handover for a UE moving fromLTE to another RAT.

FIG. 3 illustrates a successful inter-RAT handover for a UE moving toLTE from another RAT.

FIG. 4 illustrates an exemplary wireless communication network includingan Evolved Packet Core (EPC) network and a Fifth Generation (5G) Core(5GC) network.

FIG. 5 illustrates an exemplary method implemented by a UE to supportintra-RAT handover with core network change.

FIG. 6 illustrates a procedure implemented by a UE following asuccessful intra-RAT handover with a core network change.

FIG. 7 illustrates a first exemplary procedure implemented by a UEfollowing a failed intra-RAT handover with a core network change.

FIG. 8 illustrates a second exemplary procedure implemented by a UEfollowing a failed intra-RAT handover with a core network change.

FIG. 9 illustrates a third exemplary procedure implemented by a UEfollowing a failed intra-RAT handover with a core network change.

FIG. 10 illustrates an exemplary method implemented by a base station.

FIG. 11 illustrates an exemplary UE according to an embodiment.

FIG. 12 illustrates an exemplary base station according to anembodiment.

FIG. 13 illustrates exemplary UE according to another embodiment.

FIG. 14 illustrates an exemplary base station according to anotherembodiment.

FIG. 15 illustrates an exemplary wireless network according to anembodiment.

FIG. 16 illustrates an exemplary UE according to an embodiment.

FIG. 17 illustrates an exemplary virtualization environment according toan embodiment.

FIG. 18 illustrates an exemplary telecommunication network connected viaan intermediate network to a host computer according to an embodiment.

FIG. 19 illustrates an exemplary host computer communicating via a basestation with a user equipment over a partially wireless connectionaccording to an embodiment.

FIGS. 20-23 illustrate exemplary methods implemented in a communicationsystem, according to an embodiment.

DETAILED DESCRIPTION

The present disclosure relates to procedures supporting intra-RAThandovers with a change in core network (e.g., from an EPC to a 5GC orvice versa). Exemplary embodiments of the disclosure are described inthe context of a handover between two base stations connectedrespectively to an EPC network and to a 5GC network. A 5GC network is anext generation core network according to the 3GPP 5G standard which iscurrently under development.

FIG. 1 illustrates a wireless communication network 10 comprising aplurality of base stations 20, 30 and 40, some of which connect to anEPC network 50 and some of which connect to a 5GC network 60. In theexemplary embodiments disclosed, the base stations 20 connected to theEPC network 50 comprise conventional eNBs implementing the LTE airinterface specification, also known as E-UTRA. The base stations 30connecting to the 5GC network 60 comprise Next Generation eNBs (ng-eNBs)implementing the E-UTRA air interface. The base stations 40 connectingto the 5GC network 60 comprise 5G NodeBs (gNBs) implementing the NewRadio (NR) air interface specification. The eNBs 20 and ng-eNBs 30 arereferred to herein generically as E-UTRA base stations and are part ofan Evolved Universal Mobile Telecommunications System (UMTS) TerrestrialRadio Access Network (EUTRAN) 25. Some networks 10 may also include basestations that connect to both the EPC network 50 and the 5GC network 60.

A UE 100 is shown in FIG. 1 . The UE 100 is connected to one of the eNBs20 connected to the EPC network 50, but is being handed over to a ng-eNB30 connected to the 5GC network 60, either because it is moving towardsthe 5GC network 60 or because of a change in radio conditions. In thisscenario, a handover needs to be performed to handover the UE 100 fromthe eNB 20 connected to the EPC network 50 to the ng-eNB 30 connected tothe 5GC network 60. In this scenario, the eNB 20 and ng-eNB 30 use thesame RAT (in this case LTE) on the air interface but connect todifferent types of core networks. A similar scenario would arise for aUE 100 moving from ng-eNB 30 connected to the 5GC network 60 to a eNB 20connected to the EPC network 50. The procedures herein describedprovided solutions for intra-RAT handovers with a core network change.

The current LTE standards include procedures for intra-RAT handoverwithout a CN change and inter-RAT handovers. FIG. 2 illustrates anexemplary intra-RAT handover procedure. Intra-RAT handover in LTEwithout a CN change is performed with a RRCConnectionReconfigurationmessage including the mobilityControlInfo Information Element (IE),generated by the target base station 20 (e.g., eNB) and delivered to theUE 100 by the source base station 20. The RRCConnectionReconfigurationmessage is defined in the 3GPP standard TS 36.331 (v15.0.1 [2018-01])and enables delta configuration of the UE 100 in intra-LTE handover,where part of current UE configuration is kept for the connection withthe target base station 20, including security parameters. For asuccessful reconfiguration, the UE 100 responds with aRRCConnectionReconfigurationComplete message.

FIG. 3 illustrates an inter-RAT handover from LTE. Inter-RAT handoverfrom LTE implies to a full configuration of the UE 100, where none ofLTE-established protocol sublayers and previously used security keys arekept. A tunneling procedure is adopted, where the source base station 20(e.g., eNB) sends a MobilityFromEUTRACommand message to the UE 100containing an embedded message pertinent to the target RAT. TheMobilityFromEUTRACommand message is defined in the 3GPP standard TS36.331 (v15.0.1 [2018-01]) and is shown below. ThetargetRAT-MessageContainer and TargetRAT-type and the main contents inMobilityFromEUTRACommand message related to UE configuration in thetarget RAT. The former contains the configuration message itself fromthe target RAT and the latter defines the RAT, e.g., UTRA, GERAN. Thecurrently defined target RAT types include utra (Universal TerrestrialRadio Access), geran (GSM EDGE Radio Access Network (RAN)),cdma2000-1XRTT (cdma2000 Single-Carrier (1x) Radio TransmissionTechnology (RTT)), and cdma2000-HRPD (cdma2000 High Rate Packet Data(HRPD)). The nas-SecurityParamFromEUTRA is used for security keyderivation in UTRAN.

MobilityFromEUTRACommand Message

-- ASN1START ------------- Omitted Parts Handover ::= SEQUENCE {targetRAT-Type ENUMERATED { utra, geran, cdma2000-1XRTT, cdma2000-HRPD,spare4, spare3, spare2, spare1, ...}, targetRAT-MessageContainer OCTETSTRING, nas-SecurityParamFromEUTRA OCTET STRING (SIZE (1)) OPTIONAL, --Cond UTRAGERAN systemInformation SI-OrPSI-GERAN OPTIONAL  -- Cond PSHO }------------- Omitted Parts ------------- -- ASN1STOP

When moving from E-UTRA, specific actions are taken for successful andfailure handover cases, as specified in sections 5.4.3.4 and 5.4.3.5respectively, from 3GPP TS 36.331 (v15.0.1 [2018-01]), which arereproduced in small caps below. Note that for the successful handovercase, the procedure described below triggers the release of all E-UTRAconfigurations established.

5.4.3.4 Successful Completion of the Mobility from E-UTRA

-   -   UPON SUCCESSFULLY COMPLETING THE HANDOVER, THE CELL CHANGE ORDER        OR ENHANCED 1XRTT CS FALLBACK, THE UE SHALL:    -   1> PERFORM THE ACTIONS UPON LEAVING RRC_CONNECTED AS SPECIFIED        IN 5.3.12, WITH RELEASE CAUSE ‘OTHER’;    -   NOTE: IF THE UE PERFORMS ENHANCED 1XRTT CS FALLBACK ALONG WITH        CONCURRENT MOBILITY TO CDMA2000 HRPD AND THE CONNECTION TO        EITHER CDMA2000 1XRTT OR CDMA2000 HRPD SUCCEEDS, THEN THE        MOBILITY FROM E-UTRA IS CONSIDERED SUCCESSFUL.

5.4.3.5 Mobility from E-UTRA Failure

-   -   THE UE SHALL:    -   1> IF T304 EXPIRES (MOBILITY FROM E-UTRA FAILURE); OR    -   1> IF THE UE DOES NOT SUCCEED IN ESTABLISHING THE CONNECTION TO        THE TARGET RADIO ACCESS TECHNOLOGY; OR    -   1> IF THE UE IS UNABLE TO COMPLY WITH (PART OF) THE        CONFIGURATION INCLUDED IN THE MOBILITYFROMEUTRACOMMAND MESSAGE;        OR    -   1> IF THERE IS A PROTOCOL ERROR IN THE INTER RAT INFORMATION        INCLUDED IN THE MOBILITYFROMEUTRACOMMAND MESSAGE, CAUSING THE UE        TO FAIL THE PROCEDURE ACCORDING TO THE SPECIFICATIONS APPLICABLE        FOR THE TARGET RAT:        -   2> STOP T304, IF RUNNING;        -   2> IF THE CS-FALLBACKINDICATOR IN THE            MOBILITYFROMEUTRACOMMAND MESSAGE WAS SET TO TRUE OR E-CSFB            WAS PRESENT:            -   3> INDICATE TO UPPER LAYERS THAT THE CS FALLBACK                PROCEDURE HAS FAILED;        -   2> REVERT BACK TO THE CONFIGURATION USED IN THE SOURCE            PCELL, EXCLUDING THE CONFIGURATION CONFIGURED BY THE            PHYSICALCONFIGDEDICATED, MAC-MAINCONFIG AND SPS-CONFIG;        -   2> INITIATE THE CONNECTION RE-ESTABLISHMENT PROCEDURE AS            SPECIFIED IN 5.3.7.

FIG. 4 illustrates an inter-RAT handover to LTE. Similar to theinter-RAT handover from LTE, handover is performed using a tunnelingscheme with the RRCConnectionReconfiguration message delivered to the UE100 via the source RAT as shown in FIG. 4 . This RRC message indicates afull configuration and does not retain any protocol sublayersestablished by the source RAT and previously derived security keys. Whenmoving to E-UTRA, specific actions are taken for failure handover case,as specified in section 5.4.2.5, from 3GPP TS 36.331 (v15.0.1[2018-01]), which is reproduced in small caps below.

5.4.2.5 T304 Expiry (Handover to E-UTRA Failure)

-   -   THE UE SHALL:    -   1> UPON T304 EXPIRY (HANDOVER TO E-UTRA AILURE):        -   2> RESET MAC;        -   2> PERFORM THE ACTIONS DEFINED FOR THIS FAILURE CASE AS            DEFINED IN THE SPECIFICATIONS APPLICABLE FOR THE OTHER RAT;

When the intra-RAT handover procedures were developed, a change in thetype of the core network was not contemplated so these procedures wouldlikely fail in the scenarios under consideration. The procedures forinter-RAT in LTE could be adapted to facilitate an intra-RAT handoverwith a CN change, since security parameters and bearer handling aredifferent for each CN, while the Packet Data Convergence Protocol (PDCP)configuration might also be changed. However, the inter-RAT handoverprocedures currently defined in LTE would require the UE 100 to enter anIDLE mode and then re-establish a connection with the target node (e.g.,eNB or ng-eNB).

In exemplary embodiments of the present disclosure, theMobilityFromEUTRACommand message defined in LTE for inter-RAT handoversis reused for intra-RAT handovers with a core network change. When a UE100 is instructed to perform an intra-LTE handover from a source basestation 20 connected to EPC to a target base station 30 connected to5GC, or vice versa, the target node prepares aRRCConnectionReconfiguration message which it sends to the source node(e.g., eNB 20 or ng-eNB 30) via the X2, Xn, S1 or NG interfaces. Thesource node then embeds the RRCConnectionReconfiguration message insidea container called MobilityFromEUTRACommand setting the parametertargetRAT-Type to eutra to indicate that the handover involves a changeof the core network. The modified MobilityFromEUTRACommand message isshown below.

-- ASN1START MobilityFromEUTRACommand ::= SEQUENCE {rrc-TransactionIdentifier RRC-TransactionIdentifier, criticalExtensionsCHOICE { c1 CHOICE{ MobilityFromEUTRACommand-r8MobilityFromEUTRACommand-r8-IEs, MobilityFromEUTRACommand-r9MobilityFromEUTRACommand-r9-IEs, spare2 NULL, spare1 NULL },criticalExtensionsFuture SEQUENCE { } } }MobilityFromEUTRACommand-r8-IEs ::= SEQUENCE { cs-FallbackIndicatorBOOLEAN, purpose CHOICE{ handover Handover, cellChangeOrderCellChangeOrder }, nonCriticalExtensionMobilityFromEUTRACommand-v8a0-IEs OPTIONAL } ------------------------Omitted irrelevant parts ------------------------ Handover ::= SEQUENCE{ targetRAT-Type ENUMERATED { utra, geran, cdma2000-1XRTT,cdma2000-HRPD, eutra, spare3, spare2, spare1, ...},targetRAT-MessageContainer OCTET STRING, nas-SecurityParamFromEUTRAOCTET STRING (SIZE (1)) OPTIONAL, -- Cond UTRAGERAN systemInformationSI-OrPSI-GERAN OPTIONAL  -- Cond PSHO } --------------------------Omitted irrelevant parts -------------------------- -- ASN1STOP

As the UE 100 receives the MobilityFromEUTRACommand, the UE 100 willdecode the targetRAT-MessageContainer as a RRCConnectionReconfigurationas the targetRAT-Type is set to eutra and the UE 100 will perform theprocedures as specified in 36.331 (v15.0.1 [2018-01]) clause 5.4.2.3‘Reception of the RRCConnectionReconfiguration by the UE. If theprocedure is successful, the UE 100 enters RRC_CONNECTED and theprocedure ends.

For inter-RAT handover in LTE, different procedures are currentlydefined for successful handover depending on whether the UE 100 ismoving from E-UTRA and to E-UTRA. For intra-LTE with CN change case,both procedures should be performed since the UE is going from E-UTRA toE-UTRA.

Successful Intra-RAT Handover with CN Change

Because this RRCConnectionReconfiguration was triggered by a receptionof the MobilityFromEUTRACommand, the successful completion of theRRCConnectionReconfiguration will result in a successful completion ofthe mobility from E-UTRA (as specified in 36.331 v15.0.1 [2018-01]clause 5.4.3.4). Currently, this clause indicates that the UE 100 shouldleave RRC_CONNECTED and release all radio resources and the RRCconnection. Since the UE 100 has setup radio E-UTRA radio resources inthe target RAT, this would imply that the UE 100 would lose thisconnection. To properly handle the successful handover in intra-RAT withtargetRAT-Type is set to eutra in the MobilityFromEUTRACommand message,the RRC procedures specified in section 5.4.3.4 from TR 36.331 (v15.0.1[2018-01]), are only executed if the targetRAT-Type is not set to eutrain the MobilityFromEUTRACommand message. Alternatively, thespecification lists all the options the targetRAT-Type can be set toaccept eutra (i.e., utra, geran, cdma2000-1xRTT, cdma2000-HRPD, or anynew value introduced in the spare values or after the extension, e.g.,nr).

An example of the modified specification for successful handover isshown in small caps below, with the changes highlighted:

5.4.3.4 Successful Completion of the Mobility from E-UTRA

-   -   UPON SUCCESSFULLY COMPLETING THE HANDOVER, THE CELL CHANGE ORDER        OR ENHANCED 1XRTT [CIRCUIT-SWITCHED] CS FALLBACK [CSFB], THE UE        SHALL:    -   1> IF THE TARGETRAT-TYPE IN THE RECEIVED        MOBILITYFROMEUTRACOMMAND IS SET TO EUTRA:        -   2> THE PROCEDURE ENDS;    -   1> ELSE:        -   2> PERFORM THE ACTIONS UPON LEAVING RRC_CONNECTED AS            SPECIFIED IN 5.3.12, WITH RELEASE CAUSE ‘OTHER’;    -   NOTE: IF THE UE PERFORMS ENHANCED 1XRTT CS FALLBACK ALONG WITH        CONCURRENT MOBILITY TO CDMA2000 HRPD AND THE CONNECTION TO        EITHER CDMA2000 1xRTT OR CDMA2000 HRPD SUCCEEDS, THEN THE        MOBILITY FROM E-UTRA IS CONSIDERED SUCCESSFUL.        Intra-RAT Handover with CN Change Failure

When performing the procedures for RRCConnectionReconfiguration message,the timer T304 is started. If the expiry of timer T304 happens, bothfailure procedures from handover to E-UTRA and mobility from E-UTRA aretriggered, which are specified in clauses 5.4.2.5 and 5.4.3.5respectively, in 36.331 (v15.0.1 [2018-01]). However, it is only neededto trigger the failure procedure once, and none of the proceduresconsider storing the handover failure information.

To properly handle the failure of inter-RAT handover with targetRAT-Typeset to eutra in the MobilityFromEUTRACommand message, the UE 100 shouldperform only one RRC procedure chain in case of failure (T304 expiry),i.e., do not perform the failure process of E-UTRA inter-RAT handoverwith CN change in multiple sections in TR 36.331 (v15.0.1 [2018-01]).The RRC procedures should be specified as in (or refer to) section5.3.5.6 from TR 36.331 (v15.0.1 [2018-01]), which correspond to failurehandling for E-UTRA intra-RAT handover case.

Three examples of the modified LTE specification are shown below, withthe changes to support intra-RAT handover.

Example 1 for Intra-LTE Handover with CN Change Failure

5.4.3.5 Mobility from E-UTRA Failure

The UE shall:

-   -   1> IF THE TARGETRAT-TYPE IN THE RECEIVED        MOBILITYFROMEUTRACOMMAND IS SET TO EUTRA:        -   2> PERFORM THE PROCEDURES AS SPECIFIED IN 5.4.2.5;    -   1> ELSE:        -   2> IF T304 EXPIRES (MOBILITY FROM E-UTRA FAILURE); OR        -   2> IF THE UE DOES NOT SUCCEED IN ESTABLISHING THE CONNECTION            TO THE TARGET RADIO ACCESS TECHNOLOGY; OR        -   2> IF THE UE IS UNABLE TO COMPLY WITH (PART OF) THE            CONFIGURATION INCLUDED IN THE MOBILITYFROMEUTRACOMMAND            MESSAGE; OR        -   2> IF THERE IS A PROTOCOL ERROR IN THE INTER RAT INFORMATION            INCLUDED IN THE MOBILITYFROMEUTRACOMMAND MESSAGE, CAUSING            THE UE TO FAIL THE PROCEDURE ACCORDING TO THE SPECIFICATIONS            APPLICABLE FOR THE TARGET RAT:            -   3> STOP T304, IF RUNNING;            -   3> IF THE CS-FALLBACKINDICATOR IN THE                MOBILITYFROMEUTRACOMMAND MESSAGE WAS SET TO TRUE OR                E-CSFB WAS PRESENT:                -   4> INDICATE TO UPPER LAYERS THAT THE CS FALLBACK                    PROCEDURE HAS FAILED;            -   3> REVERT BACK TO THE CONFIGURATION USED IN THE SOURCE                PCELL, EXCLUDING THE CONFIGURATION CONFIGURED BY THE                PHYSICALCONFIGDEDICATED, MAC-MAINCONFIG AND SPS-CONFIG;            -   3> INITIATE THE CONNECTION RE-ESTABLISHMENT PROCEDURE AS                SPECIFIED IN 5.3.7;    -   NOTE: FOR ENHANCED CS FALLBACK TO CDMA2000 1XRTT, THE ABOVE UE        BEHAVIOR APPLIES ONLY WHEN THE UE IS ATTEMPTING THE ENHANCED        1XRTT CS FALLBACK AND CONNECTION TO THE TARGET RADIO ACCESS        TECHNOLOGY FAILS OR IF THE UE IS ATTEMPTING ENHANCED 1XRTT CS        FALLBACK ALONG WITH CONCURRENT MOBILITY TO CDMA2000 HRPD AND        CONNECTION TO BOTH THE TARGET RADIO ACCESS TECHNOLOGIES FAILS.

5.4.2.4 Reconfiguration Failure

THE UE SHALL:

-   -   1> IF THE UE IS UNABLE TO COMPLY WITH (PART OF) THE        CONFIGURATION INCLUDED IN THE RRCCONNECTIONRECONFIGURATION        MESSAGE:        -   2> IF THE SOURCE RAT THAT SENT THE            RRCCONNECTIONRECONFIGURATION MESSAGE IS E-UTRA:            -   3> PERFORM THE ACTIONS DEFINED IN INTRA-RAT HANDOVER                FAILURE PROCEDURE AS SPECIFIED IN 5.3.5.6;        -   2> ELSE:            -   3> PERFORM THE ACTIONS DEFINED FOR THIS FAILURE CASE AS                DEFINED IN THE SPECIFICATIONS APPLICABLE FOR THE OTHER                RAT;    -   NOTE 1: THE UE MAY APPLY ABOVE FAILURE HANDLING ALSO IN CASE THE        RRCCONNECTIONRECONFIGURATION MESSAGE CAUSES A PROTOCOL ERROR FOR        WHICH THE GENERIC ERROR HANDLING AS DEFINED IN 5.7 SPECIFIES        THAT THE UE SHALL IGNORE THE MESSAGE.    -   NOTE 2: IF THE UE IS UNABLE TO COMPLY WITH PART OF THE        CONFIGURATION, IT DOES NOT APPLY ANY PART OF THE CONFIGURATION,        I.E. THERE IS NO PARTIAL SUCCESS/FAILURE.

5.4.2.5 T304 Expiry (Handover to E-UTRA Failure)

THE UE SHALL:

-   -   1> UPON T304 EXPIRY (HANDOVER TO E-UTRA FAILURE):        -   2> IF THE SOURCE RAT THAT SENT THE            RRCCONNECTIONRECONFIGURATION MESSAGE IS E-UTRA:            -   3> PERFORM THE ACTIONS DEFINED IN INTRA-RAT HANDOVER                FAILURE PROCEDURE AS SPECIFIED IN 5.3.5.6;        -   2> ELSE:            -   3> RESET MAC;            -   3> PERFORM THE ACTIONS DEFINED FOR THIS FAILURE CASE AS                DEFINED IN THE SPECIFICATIONS APPLICABLE FOR THE OTHER                RAT;                Example 2 for Intra-LTE Handover with CN Change Failure

5.4.3.5 Mobility from E-UTRA Failure

THE UE SHALL:

-   -   1> IF THE TARGETRAT-TYPE IN THE RECEIVED        MOBILITYFROMEUTRACOMMAND IS SET TO EUTRA:        -   2> PERFORM THE ACTIONS DEFINED IN INTRA-RAT HANDOVER FAILURE            PROCEDURE AS SPECIFIED IN 5.3.5.6;    -   1> ELSE:        -   2> IF T304 EXPIRES (MOBILITY FROM E-UTRA FAILURE); OR        -   2> IF THE UE DOES NOT SUCCEED IN ESTABLISHING THE CONNECTION            TO THE TARGET RADIO ACCESS TECHNOLOGY; OR        -   2> IF THE UE IS UNABLE TO COMPLY WITH (PART OF) THE            CONFIGURATION INCLUDED IN THE MOBILITYFROMEUTRACOMMAND            MESSAGE; OR        -   2> IF THERE IS A PROTOCOL ERROR IN THE INTER RAT INFORMATION            INCLUDED IN THE MOBILITYFROMEUTRACOMMAND MESSAGE, CAUSING            THE UE TO FAIL THE PROCEDURE ACCORDING TO THE SPECIFICATIONS            APPLICABLE FOR THE TARGET RAT:            -   3> STOP T304, IF RUNNING;            -   3> IF THE CS-FALLBACKINDICATOR IN THE                MOBILITYFROMEUTRACOMMAND MESSAGE WAS SET TO TRUE OR                E-CSFB WAS PRESENT:                -   4> INDICATE TO UPPER LAYERS THAT THE CS FALLBACK                    PROCEDURE HAS FAILED;            -   3> REVERT BACK TO THE CONFIGURATION USED IN THE SOURCE                PCELL, EXCLUDING THE CONFIGURATION CONFIGURED BY THE                PHYSICALCONFIGDEDICATED, MAC-MAINCONFIG AND SPS-CONFIG;            -   3> INITIATE THE CONNECTION RE-ESTABLISHMENT PROCEDURE AS                SPECIFIED IN 5.3.7;    -   NOTE: FOR ENHANCED CS FALLBACK TO CDMA2000 1XRTT, THE ABOVE UE        BEHAVIOR APPLIES ONLY WHEN THE UE IS ATTEMPTING THE ENHANCED        1XRTT CS FALLBACK AND CONNECTION TO THE TARGET RADIO ACCESS        TECHNOLOGY FAILS OR IF THE UE IS ATTEMPTING ENHANCED 1XRTT CS        FALLBACK ALONG WITH CONCURRENT MOBILITY TO CDMA2000 HRPD AND        CONNECTION TO BOTH THE TARGET RADIO ACCESS TECHNOLOGIES FAILS.

5.4.2.4 Reconfiguration Failure

THE UE SHALL:

-   -   1> IF THE UE IS UNABLE TO COMPLY WITH (PART OF) THE        CONFIGURATION INCLUDED IN THE RRCCONNECTIONRECONFIGURATION        MESSAGE:        -   2> IF THE SOURCE RAT THAT SENT THE            RRCCONNECTIONRECONFIGURATION MESSAGE IS E-UTRA:            -   3> PERFORM THE PROCEDURES SPECIFIED IN SECTION 5.4.3.5;        -   2> ELSE:            -   3> PERFORM THE ACTIONS DEFINED FOR THIS FAILURE CASE AS                DEFINED IN THE SPECIFICATIONS APPLICABLE FOR THE OTHER                RAT;    -   NOTE 1: THE UE MAY APPLY ABOVE FAILURE HANDLING ALSO IN CASE THE        RRCCONNECTIONRECONFIGURATION MESSAGE CAUSES A PROTOCOL ERROR FOR        WHICH THE GENERIC ERROR HANDLING AS DEFINED IN 5.7 SPECIFIES        THAT THE UE SHALL IGNORE THE MESSAGE.    -   NOTE 2: IF THE UE IS UNABLE TO COMPLY WITH PART OF THE        CONFIGURATION, IT DOES NOT APPLY ANY PART OF THE CONFIGURATION,        I.E. THERE IS NO PARTIAL SUCCESS/FAILURE.

5.4.2.5 T304 Expiry (Handover to E-UTRA Failure)

THE UE SHALL:

-   -   1> UPON T304 EXPIRY (HANDOVER TO E-UTRA FAILURE):        -   2> IF THE SOURCE RAT THAT SENT THE            RRCCONNECTIONRECONFIGURATION MESSAGE IS E-UTRA:            -   3> PERFORM THE PROCEDURES SPECIFIED IN SECTION 5.4.3.5;        -   2> ELSE:            -   3> RESET MAC;            -   3> PERFORM THE ACTIONS DEFINED FOR THIS FAILURE CASE AS                DEFINED IN THE SPECIFICATIONS APPLICABLE FOR THE OTHER                RAT;                Example 3 for Intra-LTE Handover with CN Change Failure

5.4.3.5 Mobility from E-UTRA Failure

THE UE SHALL:

-   -   1> IF THE TARGETRAT-TYPE IN THE RECEIVED        MOBILITYFROMEUTRACOMMAND IS SET TO EUTRA:        -   2> PERFORM THE ACTIONS DEFINED IN INTRA-RAT HANDOVER FAILURE            PROCEDURE AS SPECIFIED IN 5.3.5.6;    -   1> ELSE:        -   2> IF T304 EXPIRES (MOBILITY FROM E-UTRA FAILURE); OR        -   2> IF THE UE DOES NOT SUCCEED IN ESTABLISHING THE CONNECTION            TO THE TARGET RADIO ACCESS TECHNOLOGY; OR        -   2> IF THE UE IS UNABLE TO COMPLY WITH (PART OF) THE            CONFIGURATION INCLUDED IN THE MOBILITYFROMEUTRACOMMAND            MESSAGE; OR        -   2> IF THERE IS A PROTOCOL ERROR IN THE INTER RAT INFORMATION            INCLUDED IN THE MOBILITYFROMEUTRACOMMAND MESSAGE, CAUSING            THE UE TO FAIL THE PROCEDURE ACCORDING TO THE SPECIFICATIONS            APPLICABLE FOR THE TARGET RAT:            -   3> STOP T304, IF RUNNING;            -   3> IF THE CS-FALLBACKINDICATOR IN THE                MOBILITYFROMEUTRACOMMAND MESSAGE WAS SET TO TRUE OR                E-CSFB WAS PRESENT:                -   4> INDICATE TO UPPER LAYERS THAT THE CS FALLBACK                    PROCEDURE HAS FAILED;            -   3> REVERT BACK TO THE CONFIGURATION USED IN THE SOURCE                PCELL, EXCLUDING THE CONFIGURATION CONFIGURED BY THE                PHYSICALCONFIGDEDICATED, MAC-MAINCONFIG AND SPS-CONFIG;            -   3> INITIATE THE CONNECTION RE-ESTABLISHMENT PROCEDURE AS                SPECIFIED IN 5.3.7;    -   NOTE: For enhanced CS fallback to CDMA2000 1xRTT, the above UE        behavior applies only when the UE is attempting the enhanced        1xRTT CS fallback and connection to the target radio access        technology fails or if the UE is attempting enhanced 1xRTT CS        fallback along with concurrent mobility to CDMA2000 HRPD and        connection to both the target radio access technologies fails.

5.4.2.4 Reconfiguration Failure

THE UE SHALL:

-   -   1> IF THE UE IS UNABLE TO COMPLY WITH (PART OF) THE        CONFIGURATION INCLUDED IN THE RRCCONNECTIONRECONFIGURATION        MESSAGE:        -   2> IF THE SOURCE RAT THAT SENT THE            RRCCONNECTIONRECONFIGURATION MESSAGE IS E-UTRA:            -   3> PERFORM THE ACTIONS DEFINED IN INTRA-RAT HANDOVER                FAILURE PROCEDURE AS SPECIFIED IN 5.3.5.6;        -   2> ELSE:            -   3> PERFORM THE ACTIONS DEFINED FOR THIS FAILURE CASE AS                DEFINED IN THE SPECIFICATIONS APPLICABLE FOR THE OTHER                RAT;    -   NOTE 1: THE UE MAY APPLY ABOVE FAILURE HANDLING ALSO IN CASE THE        RRCCONNECTIONRECONFIGURATION MESSAGE CAUSES A PROTOCOL ERROR FOR        WHICH THE GENERIC ERROR HANDLING AS DEFINED IN 5.7 SPECIFIES        THAT THE UE SHALL IGNORE THE MESSAGE.    -   NOTE 2: IF THE UE IS UNABLE TO COMPLY WITH PART OF THE        CONFIGURATION, IT DOES NOT APPLY ANY PART OF THE CONFIGURATION,        I.E. THERE IS NO PARTIAL SUCCESS/FAILURE.

5.4.2.5 T304 Expiry (Handover to E-UTRA Failure)

THE UE SHALL:

-   -   1> UPON T304 EXPIRY (HANDOVER TO E-UTRA FAILURE):        -   2> IF THE SOURCE RAT THAT SENT THE            RRCCONNECTIONRECONFIGURATION MESSAGE IS E-UTRA:            -   3> PERFORM THE ACTIONS DEFINED IN INTRA-RAT HANDOVER                FAILURE PROCEDURE AS SPECIFIED IN 5.3.5.6;        -   2> ELSE:            -   3> RESET MAC;            -   3> PERFORM THE ACTIONS DEFINED FOR THIS FAILURE CASE AS                DEFINED IN THE SPECIFICATIONS APPLICABLE FOR THE OTHER                RAT;

FIG. 5 illustrates an exemplary method 300 implemented by a UE 100 tosupport intra-RAT handovers with a core network change as hereindescribed. More particularly, the method 300 is implemented by a UE 100in a wireless communication network 10 when performing a handover from asource node (e.g., eNB 20) connected to a first core network (e.g., EPC50) to a target node (e.g., ng-eNB 30) connected to a second corenetwork (e.g., 5GC 60). In one example, the UE 100 receives, from thesource node, a mobility command including an indication of the radioaccess technology (RAT) used by the target node and a message containercontaining configuration information for the target node (block 310).The UE 100 determines based on the indication of the RAT used by thetarget node whether to treat the handover as an inter-RAT handover or asan intra-RAT handover with a core network change (block 320). Based onthe determination, the UE 100 performs a RRC procedure for one of aninter-RAT handover or an inter-RAT handover (block 330).

In some embodiments of the method 300, determining whether to treat thehandover as an inter-RAT handover or as an intra-RAT handover with acore network change comprises determining to treat the handover as anintra-RAT handover with a core network change when the indicationindicates a first type of RAT.

In some embodiments of the method 300, the first RAT type is EvolvedUniversal Mobile Telecommunications System (UMTS) Terrestrial RadioAccess (E-UTRA).

In some embodiments of the method 300, performing a radio resourcecontrol procedure based on the determination comprises, uponsuccessfully completing the handover, remaining in a Radio ResourceControl Connected (RRC_CONNECTED) state and ending Mobility from E-UTRAprocedures.

In some embodiments of the method 300, performing a radio resourcecontrol procedure based on the determination comprises, upon occurrenceof a mobility failure, performing an intra-RAT handover failureprocedure.

In some embodiments, the mobility failure comprises a reconfigurationfailure, handover to E-UTRA failure, or a timer expiration.

In some embodiments of the method 300, the mobility command comprises anE-UTRA MobilityFromEUTRACommand message.

In some embodiments of the method 300, the message container contains anE-UTRA RRCConnectionReconfiguration message from the target node.

In some embodiments of the method 300, the first core network comprisesan Evolved Packet Core (EPC) network and the second core networkcomprise a 5th Generation Core (5GC) network.

In some embodiments of the method 300, the first core network comprisesa 5th Generation Core (5GC) network and the second core network comprisean Evolved Packet Core (EPC) network.

FIGS. 6-9 illustrate exemplary RRC procedures for the case of anintra-RAT handover with a core network change.

FIG. 6 illustrates an exemplary RRC procedure 400 for a successfulhandover from the source node to a target node. The UE 100 successfullycompletes the mobility from E-UTRA procedure (block 405). After thesuccessful completion of the mobility from E-UTRA procedure, the UE 100checks whether the targetRAT-Type indication is set to eutra (block410). If the targetRAT-Type indication is set to eutra, the procedure400 ends (block 420). If the targetRAT-Type indication is not set toeutra, the UE 100 performs the RRC procedures for successful competitionof mobility from E-UTRA (block 415).

FIG. 7 illustrates an exemplary RRC procedure 425 in case of a mobilityfailure according to a first embodiment. The E-UTRA inter-RAT mobilityfailure procedure is triggered by the mobility failure (block 430). TheUE 100 checks whether the targetRAT-Type indication is set to eutra(block 435). If the targetRAT-Type indication is not set to eutra, theUE 100 performs RRC procedures for the mobility case, i.e., mobilityfrom E-UTRA failure or mobility to E-UTRA failure. E-UTRA (block 440)and the procedure ends (block 450). If the targetRAT-Type indication isset to eutra, for handover to E-UTRA failure, the UE 100 performs theRRC procedures for intra-RAT handover failure (block 445) and theprocedure ends (block 450).

FIG. 8 illustrates an exemplary RRC procedure 460 in case of a mobilityfailure according to a second embodiment. The E-UTRA inter-RAT mobilityfailure procedure is triggered by the mobility failure (block 465). TheUE 100 checks whether the targetRAT-Type indication is set to eutra(block 470). If the targetRAT-Type indication is not set to eutra, theUE 100 performs RRC procedures for the mobility case, i.e., mobilityfrom E-UTRA failure or mobility to E-UTRA failure. E-UTRA (block 475)and the procedure ends (block 485). If the targetRAT-Type indication isset to eutra, for handover from E-UTRA failure, the UE 100 performs theRRC procedures for intra-RAT handover failure (block 480) and theprocedure ends (block 485).

FIG. 9 illustrates an exemplary RRC procedure 500 in case of a mobilityfailure according to a third embodiment. The E-UTRA inter-RAT mobilityfailure procedure is triggered by the mobility failure (block 505). TheUE 100 checks whether the targetRAT-Type indication is set to eutra(block 510). If the targetRAT-Type indication is not set to eutra, theUE 100 performs RRC procedures for the mobility case, i.e., mobilityfrom E-UTRA failure or mobility to E-UTRA failure (block 515) and theprocedure ends (block 525). If the targetRAT-Type indication is set toeutra, for handover to or from E-UTRA failure, the UE 100 performs theRRC procedures for reception of the RRCConnectionReconfiguration (block520) and the procedure ends (block 525).

FIG. 10 illustrates an exemplary method 550 performed by a source node20, 30 (e.g., eNB 20 or ng-eNB 30). The source node 20, 30 sends amobility command including a radio access technology (RAT) typeindication and a message container containing configuration informationfor the target node (e.g., eNB 20 or ng-eNB 30) (block 560). The sourcenode 20, 30 sets the RAT type indication in the mobility command to apredetermined value to indicate to the UE that the handover involves acore network change (block 570).

In some embodiments of the method 550, the source node and target nodecomprise E-UTRA base stations.

In some embodiments of the method 550, the mobility command comprises anE-UTRA MobilityFromEUTRACommand message.

In some embodiments of the method 550, the message container contains anE-UTRA RRCConnectionReconfiguration message from the target node.

In some embodiments of the method 550, the first core network comprisesan Evolved Packet Core (EPC) network and the second core networkcomprises a 5th Generation Core (5GC) network.

In some embodiments of the method 550, the first core network comprisesa 5th Generation Core (5GC) network and the second core network comprisean Evolved Packet Core (EPC) network.

In some embodiments of the method 550, setting the RAT type indicationin the mobility command to a predetermined value comprises setting theRAT type indication in the mobility command to eutra,

FIG. 11 illustrates a UE 100 in accordance with one or more embodiments.The UE 100 comprises an antenna array 110 having multiple antennas 115,a receiving (RX) module 120, a determining module 130 and a RRC module140. The various modules 120, 130, and 140 can be implemented byhardware and/or by software code that is executed by one or moreprocessors or processing circuits. The receiving module 120 isconfigured to receive, from the source node (e.g., eNB 20 or ng-eNB 30),a mobility command including an indication of the radio accesstechnology (RAT) used by the target node (e.g., eNB 20 or ng-eNB 30) anda message container containing configuration information for the targetnode. The determining module 130 is configured to determine, based onthe indication of the RAT used by the target node, whether to treat thehandover as an inter-RAT handover or as an intra-RAT handover with acore network change The RRC module 140 is configured to perform a RRCprocedure for one of an inter-RAT handover or an inter-RAT handover.

FIG. 12 illustrates an E-UTRA base station 200 in accordance with one ormore embodiments. The E-UTRA base station 200 comprises an antenna array210 having multiple antennas 215, a sending module 220 and a settingmodule 230. The modules 220 and 230 can be implemented by hardwareand/or by software code that is executed by one or more processors orprocessing circuits. The sending module 220 is configured to send amobility command including a radio access technology (RAT) typeindication and a message container containing configuration informationfor a target base station. The setting module 230 is configured to setthe RAT type indication in the mobility command to a predetermined valueto indicate to the UE that the handover involves a core network 50, 60change.

FIG. 13 illustrates a UE 600 according to another embodiment that isconfigured to implement the methods as herein described. The UE 600comprises an antenna array 610 with multiple antenna elements 615, acommunication circuit 620, a processing circuit 630, and memory 640.

The communication circuit 620 is coupled to the antenna elements 615 andcomprises the radio frequency (RF) circuitry needed for transmitting andreceiving signals over a wireless communication channel. The processingcircuit 630 controls the overall operation of the UE 600 and processesthe signals transmitted to or received by the UE 600. The processingcircuit 630 is configured to perform the method 300 shown in FIG. 5 , aswell as the procedures 400, 425, 460 and 500 shown in FIGS. 6-9respectively. The processing circuit 630 may comprise one or moremicroprocessors, hardware, firmware, or a combination thereof.

Memory 640 comprises both volatile and non-volatile memory for storingcomputer program code and data needed by the processing circuit 630 foroperation. Memory 640 may comprise any tangible, non-transitorycomputer-readable storage medium for storing data including electronic,magnetic, optical, electromagnetic, or semiconductor data storage.Memory 640 stores a computer program 650 comprising executableinstructions that configure the processing circuit 630 to implementmethods 300 according to FIG. 5 as described herein. In general,computer program instructions and configuration information are storedin a non-volatile memory, such as a ROM, erasable programmable read onlymemory (EPROM) or flash memory. Temporary data generated duringoperation may be stored in a volatile memory, such as a random accessmemory (RAM). In some embodiments, computer program 650 for configuringthe processing circuit 630 as herein described may be stored in aremovable memory, such as a portable compact disc, portable digitalvideo disc, or other removable media. The computer program 650 may alsobe embodied in a carrier such as an electronic signal, optical signal,radio signal, or computer readable storage medium.

FIG. 14 illustrates a base station 700 according to another embodimentthat is configured to implement the methods as herein described. Thebase station 700 comprises an antenna array 710 with multiple antennaelements 715, a communication circuit 720, a processing circuit 730, andmemory 740.

The communication circuit 720 is coupled to the antenna elements 715 andcomprises the radio frequency (RF) circuitry needed for transmitting andreceiving signals over a wireless communication channel. The processingcircuit 730 controls the overall operation of the base station 700 andprocesses the signals transmitted to or received by the UE 600. Theprocessing circuit 730 is configured to perform the method 550 shown inFIG. 10 . The processing circuit 730 may comprise one or moremicroprocessors, hardware, firmware, or a combination thereof.

Memory 740 comprises both volatile and non-volatile memory for storingcomputer program code and data needed by the processing circuit 730 foroperation. Memory 740 may comprise any tangible, non-transitorycomputer-readable storage medium for storing data including electronic,magnetic, optical, electromagnetic, or semiconductor data storage.Memory 740 stores a computer program 750 comprising executableinstructions that configure the processing circuit 730 to implementmethods 550 according to FIG. 10 as described herein. In general,computer program instructions and configuration information are storedin a non-volatile memory, such as a ROM, erasable programmable read onlymemory (EPROM) or flash memory. Temporary data generated duringoperation may be stored in a volatile memory, such as a random accessmemory (RAM). In some embodiments, computer program 750 for configuringthe processing circuit 730 as herein described may be stored in aremovable memory, such as a portable compact disc, portable digitalvideo disc, or other removable media. The computer program 750 may alsobe embodied in a carrier such as an electronic signal, optical signal,radio signal, or computer readable storage medium.

The methods and apparatus as herein described enable intra-RAT handoverwith CN change with proper functioning of success and failure cases,which will prevent ambiguity in the actions performed in RRC. The legacyprocedure for intra-RAT handover with CN change may not work as thewhole E-UTRA configuration would be released after a successfulhandover, while multiple failure procedures would be triggered. Withoutthe changes proposed in this disclosure, a UE will be forced to go viathe IDLE mode when performing an intra-LTE inter-system handover, whichcould cause a major service disruption (e.g., if the UE already hasactive delay sensitive services/bearers).

Note that the apparatuses described above may perform the methods hereinand any other processing by implementing any functional means, modules,units, or circuitry. In one embodiment, for example, the apparatusescomprise respective circuits or circuitry configured to perform thesteps shown in the method figures. The circuits or circuitry in thisregard may comprise circuits dedicated to performing certain functionalprocessing and/or one or more microprocessors in conjunction withmemory. For instance, the circuitry may include one or moremicroprocessors or microcontrollers, as well as other digital hardware,which may include digital signal processors (DSPs), special-purposedigital logic, and the like. The processing circuitry may be configuredto execute program code stored in memory, which may include one orseveral types of memory such as read-only memory (ROM), random-accessmemory, cache memory, flash memory devices, optical storage devices,etc. Program code stored in memory may include program instructions forexecuting one or more telecommunications and/or data communicationsprotocols as well as instructions for carrying out one or more of thetechniques described herein, in several embodiments. In embodiments thatemploy memory, the memory stores program code that, when executed by theone or more processors, carries out the techniques described herein.

Additional Embodiments

Although the subject matter described herein may be implemented in anyappropriate type of system using any suitable components, theembodiments disclosed herein are described in relation to a wirelessnetwork, such as the example wireless network illustrated in FIG. 15 .For simplicity, the wireless network of FIG. 15 only depicts network1106, network nodes 1160 and 1160 b, and WDs 1110, 1110 b, and 1110 c.In practice, a wireless network may further include any additionalelements suitable to support communication between wireless devices orbetween a wireless device and another communication device, such as alandline telephone, a service provider, or any other network node or enddevice. Of the illustrated components, network node 1160 and wirelessdevice (WD) 1110 are depicted with additional detail. The wirelessnetwork may provide communication and other types of services to one ormore wireless devices to facilitate the wireless devices' access toand/or use of the services provided by, or via, the wireless network.

The wireless network may comprise and/or interface with any type ofcommunication, telecommunication, data, cellular, and/or radio networkor other similar type of system. In some embodiments, the wirelessnetwork may be configured to operate according to specific standards orother types of predefined rules or procedures. Thus, particularembodiments of the wireless network may implement communicationstandards, such as Global System for Mobile Communications (GSM),Universal Mobile Telecommunications System (UMTS), Long Term Evolution(LTE), Narrowband Internet of Things (NB-IoT), and/or other suitable 2G,3G, 4G, or 5G standards; wireless local area network (WLAN) standards,such as the IEEE 802.11 standards; and/or any other appropriate wirelesscommunication standard, such as the Worldwide Interoperability forMicrowave Access (WiMax), Bluetooth, Z-Wave and/or ZigBee standards.

Network 1106 may comprise one or more backhaul networks, core networks,IP networks, public switched telephone networks (PSTNs), packet datanetworks, optical networks, wide-area networks (WANs), local areanetworks (LANs), wireless local area networks (WLANs), wired networks,wireless networks, metropolitan area networks, and other networks toenable communication between devices.

Network node 1160 and WD 1110 comprise various components described inmore detail below. These components work together in order to providenetwork node and/or wireless device functionality, such as providingwireless connections in a wireless network. In different embodiments,the wireless network may comprise any number of wired or wirelessnetworks, network nodes, base stations, controllers, wireless devices,relay stations, and/or any other components or systems that mayfacilitate or participate in the communication of data and/or signalswhether via wired or wireless connections.

As used herein, network node refers to equipment capable, configured,arranged and/or operable to communicate directly or indirectly with awireless device and/or with other network nodes or equipment in thewireless network to enable and/or provide wireless access to thewireless device and/or to perform other functions (e.g., administration)in the wireless network. Examples of network nodes include, but are notlimited to, access points (APs) (e.g., radio access points), basestations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs(eNBs) and NR NodeBs (gNBs)). Base stations may be categorized based onthe amount of coverage they provide (or, stated differently, theirtransmit power level) and may then also be referred to as femto basestations, pico base stations, micro base stations, or macro basestations. A base station may be a relay node or a relay donor nodecontrolling a relay. A network node may also include one or more (orall) parts of a distributed radio base station such as centralizeddigital units and/or remote radio units (RRUs), sometimes referred to asRemote Radio Heads (RRHs). Such remote radio units may or may not beintegrated with an antenna as an antenna integrated radio. Parts of adistributed radio base station may also be referred to as nodes in adistributed antenna system (DAS). Yet further examples of network nodesinclude multi-standard radio (MSR) equipment such as MSR BSs, networkcontrollers such as radio network controllers (RNCs) or base stationcontrollers (BSCs), base transceiver stations (BTSs), transmissionpoints, transmission nodes, multi-cell/multicast coordination entities(MCEs), core network nodes (e.g., MSCs, MMEs), O&M nodes, OSS nodes, SONnodes, positioning nodes (e.g., E-SMLCs), and/or MDTs. As anotherexample, a network node may be a virtual network node as described inmore detail below. More generally, however, network nodes may representany suitable device (or group of devices) capable, configured, arranged,and/or operable to enable and/or provide a wireless device with accessto the wireless network or to provide some service to a wireless devicethat has accessed the wireless network.

In FIG. 15 , network node 1160 includes processing circuitry 1170,device readable medium 1180, interface 1190, auxiliary equipment 1184,power source 1186, power circuitry 1187, and antenna 1162. Althoughnetwork node 1160 illustrated in the example wireless network of FIG. 15may represent a device that includes the illustrated combination ofhardware components, other embodiments may comprise network nodes withdifferent combinations of components. It is to be understood that anetwork node comprises any suitable combination of hardware and/orsoftware needed to perform the tasks, features, functions and methodsdisclosed herein. Moreover, while the components of network node 1160are depicted as single boxes located within a larger box, or nestedwithin multiple boxes, in practice, a network node may comprise multipledifferent physical components that make up a single illustratedcomponent (e.g., device readable medium 1180 may comprise multipleseparate hard drives as well as multiple RAM modules).

Similarly, network node 1160 may be composed of multiple physicallyseparate components (e.g., a NodeB component and a RNC component, or aBTS component and a BSC component, etc.), which may each have their ownrespective components. In certain scenarios in which network node 1160comprises multiple separate components (e.g., BTS and BSC components),one or more of the separate components may be shared among severalnetwork nodes. For example, a single RNC may control multiple NodeBs. Insuch a scenario, each unique NodeB and RNC pair, may in some instancesbe considered a single separate network node. In some embodiments,network node 1160 may be configured to support multiple radio accesstechnologies (RATs). In such embodiments, some components may beduplicated (e.g., separate device readable medium 1180 for the differentRATs) and some components may be reused (e.g., the same antenna 1162 maybe shared by the RATs). Network node 1160 may also include multiple setsof the various illustrated components for different wirelesstechnologies integrated into network node 1160, such as, for example,GSM, WCDMA, LTE, NR, WiFi, or Bluetooth wireless technologies. Thesewireless technologies may be integrated into the same or different chipor set of chips and other components within network node 1160.

Processing circuitry 1170 is configured to perform any determining,calculating, or similar operations (e.g., certain obtaining operations)described herein as being provided by a network node. These operationsperformed by processing circuitry 1170 may include processinginformation obtained by processing circuitry 1170 by, for example,converting the obtained information into other information, comparingthe obtained information or converted information to information storedin the network node, and/or performing one or more operations based onthe obtained information or converted information, and as a result ofsaid processing making a determination.

Processing circuitry 1170 may comprise a combination of one or more of amicroprocessor, controller, microcontroller, central processing unit,digital signal processor, application-specific integrated circuit, fieldprogrammable gate array, or any other suitable computing device,resource, or combination of hardware, software and/or encoded logicoperable to provide, either alone or in conjunction with other networknode 1160 components, such as device readable medium 1180, network node1160 functionality. For example, processing circuitry 1170 may executeinstructions stored in device readable medium 1180 or in memory withinprocessing circuitry 1170. Such functionality may include providing anyof the various wireless features, functions, or benefits discussedherein. In some embodiments, processing circuitry 1170 may include asystem on a chip (SOC).

In some embodiments, processing circuitry 1170 may include one or moreof radio frequency (RF) transceiver circuitry 1172 and basebandprocessing circuitry 1174. In some embodiments, radio frequency (RF)transceiver circuitry 1172 and baseband processing circuitry 1174 may beon separate chips (or sets of chips), boards, or units, such as radiounits and digital units. In alternative embodiments, part or all of RFtransceiver circuitry 1172 and baseband processing circuitry 1174 may beon the same chip or set of chips, boards, or units.

In certain embodiments, some or all of the functionality describedherein as being provided by a network node, base station, eNB or othersuch network device may be performed by processing circuitry 1170executing instructions stored on device readable medium 1180 or memorywithin processing circuitry 1170. In alternative embodiments, some orall of the functionality may be provided by processing circuitry 1170without executing instructions stored on a separate or discrete devicereadable medium, such as in a hard-wired manner. In any of thoseembodiments, whether executing instructions stored on a device readablestorage medium or not, processing circuitry 1170 can be configured toperform the described functionality. The benefits provided by suchfunctionality are not limited to processing circuitry 1170 alone or toother components of network node 1160, but are enjoyed by network node1160 as a whole, and/or by end users and the wireless network generally.

Device readable medium 1180 may comprise any form of volatile ornon-volatile computer readable memory including, without limitation,persistent storage, solid-state memory, remotely mounted memory,magnetic media, optical media, random access memory (RAM), read-onlymemory (ROM), mass storage media (for example, a hard disk), removablestorage media (for example, a flash drive, a Compact Disk (CD) or aDigital Video Disk (DVD)), and/or any other volatile or non-volatile,non-transitory device readable and/or computer-executable memory devicesthat store information, data, and/or instructions that may be used byprocessing circuitry 1170. Device readable medium 1180 may store anysuitable instructions, data or information, including a computerprogram, software, an application including one or more of logic, rules,code, tables, etc. and/or other instructions capable of being executedby processing circuitry 1170 and, utilized by network node 1160. Devicereadable medium 1180 may be used to store any calculations made byprocessing circuitry 1170 and/or any data received via interface 1190.In some embodiments, processing circuitry 1170 and device readablemedium 1180 may be considered to be integrated.

Interface 1190 is used in the wired or wireless communication ofsignaling and/or data between network node 1160, network 1106, and/orWDs 1110. As illustrated, interface 1190 comprises port(s)/terminal(s)1194 to send and receive data, for example to and from network 1106 overa wired connection. Interface 1190 also includes radio front endcircuitry 1192 that may be coupled to, or in certain embodiments a partof, antenna 1162. Radio front end circuitry 1192 comprises filters 1198and amplifiers 1196. Radio front end circuitry 1192 may be connected toantenna 1162 and processing circuitry 1170. Radio front end circuitrymay be configured to condition signals communicated between antenna 1162and processing circuitry 1170. Radio front end circuitry 1192 mayreceive digital data that is to be sent out to other network nodes orWDs via a wireless connection. Radio front end circuitry 1192 mayconvert the digital data into a radio signal having the appropriatechannel and bandwidth parameters using a combination of filters 1198and/or amplifiers 1196. The radio signal may then be transmitted viaantenna 1162. Similarly, when receiving data, antenna 1162 may collectradio signals which are then converted into digital data by radio frontend circuitry 1192. The digital data may be passed to processingcircuitry 1170. In other embodiments, the interface may comprisedifferent components and/or different combinations of components.

In certain alternative embodiments, network node 1160 may not includeseparate radio front end circuitry 1192, instead, processing circuitry1170 may comprise radio front end circuitry and may be connected toantenna 1162 without separate radio front end circuitry 1192. Similarly,in some embodiments, all or some of RF transceiver circuitry 1172 may beconsidered a part of interface 1190. In still other embodiments,interface 1190 may include one or more ports or terminals 1194, radiofront end circuitry 1192, and RF transceiver circuitry 1172, as part ofa radio unit (not shown), and interface 1190 may communicate withbaseband processing circuitry 1174, which is part of a digital unit (notshown).

Antenna 1162 may include one or more antennas, or antenna arrays,configured to send and/or receive wireless signals. Antenna 1162 may becoupled to radio front end circuitry 1192 and may be any type of antennacapable of transmitting and receiving data and/or signals wirelessly. Insome embodiments, antenna 1162 may comprise one or moreomni-directional, sector or panel antennas operable to transmit/receiveradio signals between, for example, 2 GHz and 66 GHz. Anomni-directional antenna may be used to transmit/receive radio signalsin any direction, a sector antenna may be used to transmit/receive radiosignals from devices within a particular area, and a panel antenna maybe a line of sight antenna used to transmit/receive radio signals in arelatively straight line. In some instances, the use of more than oneantenna may be referred to as MIMO. In certain embodiments, antenna 1162may be separate from network node 1160 and may be connectable to networknode 1160 through an interface or port.

Antenna 1162, interface 1190, and/or processing circuitry 1170 may beconfigured to perform any receiving operations and/or certain obtainingoperations described herein as being performed by a network node. Anyinformation, data and/or signals may be received from a wireless device,another network node and/or any other network equipment. Similarly,antenna 1162, interface 1190, and/or processing circuitry 1170 may beconfigured to perform any transmitting operations described herein asbeing performed by a network node. Any information, data and/or signalsmay be transmitted to a wireless device, another network node and/or anyother network equipment.

Power circuitry 1187 may comprise, or be coupled to, power managementcircuitry and is configured to supply the components of network node1160 with power for performing the functionality described herein. Powercircuitry 1187 may receive power from power source 1186. Power source1186 and/or power circuitry 1187 may be configured to provide power tothe various components of network node 1160 in a form suitable for therespective components (e.g., at a voltage and current level needed foreach respective component). Power source 1186 may either be included in,or external to, power circuitry 1187 and/or network node 1160. Forexample, network node 1160 may be connectable to an external powersource (e.g., an electricity outlet) via an input circuitry or interfacesuch as an electrical cable, whereby the external power source suppliespower to power circuitry 1187. As a further example, power source 1186may comprise a source of power in the form of a battery or battery packwhich is connected to, or integrated in, power circuitry 1187. Thebattery may provide backup power should the external power source fail.Other types of power sources, such as photovoltaic devices, may also beused.

Alternative embodiments of network node 1160 may include additionalcomponents beyond those shown in FIG. 15 that may be responsible forproviding certain aspects of the network node's functionality, includingany of the functionality described herein and/or any functionalitynecessary to support the subject matter described herein. For example,network node 1160 may include user interface equipment to allow input ofinformation into network node 1160 and to allow output of informationfrom network node 1160. This may allow a user to perform diagnostic,maintenance, repair, and other administrative functions for network node1160.

As used herein, wireless device (WD) refers to a device capable,configured, arranged and/or operable to communicate wirelessly withnetwork nodes and/or other wireless devices. Unless otherwise noted, theterm WD may be used interchangeably herein with user equipment (UE).Communicating wirelessly may involve transmitting and/or receivingwireless signals using electromagnetic waves, radio waves, infraredwaves, and/or other types of signals suitable for conveying informationthrough air. In some embodiments, a WD may be configured to transmitand/or receive information without direct human interaction. Forinstance, a WD may be designed to transmit information to a network on apredetermined schedule, when triggered by an internal or external event,or in response to requests from the network. Examples of a WD include,but are not limited to, a smart phone, a mobile phone, a cell phone, avoice over IP (VoIP) phone, a wireless local loop phone, a desktopcomputer, a personal digital assistant (PDA), a wireless cameras, agaming console or device, a music storage device, a playback appliance,a wearable terminal device, a wireless endpoint, a mobile station, atablet, a laptop, a laptop-embedded equipment (LEE), a laptop-mountedequipment (LME), a smart device, a wireless customer-premise equipment(CPE), a vehicle-mounted wireless terminal device, etc. A WD may supportdevice-to-device (D2D) communication, for example by implementing a 3GPPstandard for sidelink communication, vehicle-to-vehicle (V2V),vehicle-to-infrastructure (V2I), vehicle-to-everything (V2X) and may inthis case be referred to as a D2D communication device. As yet anotherspecific example, in an Internet of Things (IoT) scenario, a WD mayrepresent a machine or other device that performs monitoring and/ormeasurements, and transmits the results of such monitoring and/ormeasurements to another WD and/or a network node. The WD may in thiscase be a machine-to-machine (M2M) device, which may in a 3GPP contextbe referred to as an MTC device. As one particular example, the WD maybe a UE implementing the 3GPP narrow band internet of things (NB-IoT)standard. Particular examples of such machines or devices are sensors,metering devices such as power meters, industrial machinery, or home orpersonal appliances (e.g., refrigerators, televisions, etc.) personalwearables (e.g., watches, fitness trackers, etc.). In other scenarios, aWD may represent a vehicle or other equipment that is capable ofmonitoring and/or reporting on its operational status or other functionsassociated with its operation. A WD as described above may represent theendpoint of a wireless connection, in which case the device may bereferred to as a wireless terminal. Furthermore, a WD as described abovemay be mobile, in which case it may also be referred to as a mobiledevice or a mobile terminal.

As illustrated, wireless device 1110 includes antenna 1111, interface1114, processing circuitry 1120, device readable medium 1130, userinterface equipment 1132, auxiliary equipment 1134, power source 1136and power circuitry 1137. WD 1110 may include multiple sets of one ormore of the illustrated components for different wireless technologiessupported by WD 1110, such as, for example, GSM, WCDMA, LTE, NR, WiFi,WiMAX, NB-IoT, or Bluetooth wireless technologies, just to mention afew. These wireless technologies may be integrated into the same ordifferent chips or set of chips as other components within WD 1110.

Antenna 1111 may include one or more antennas or antenna arrays,configured to send and/or receive wireless signals, and is connected tointerface 1114. In certain alternative embodiments, antenna 1111 may beseparate from WD 1110 and be connectable to WD 1110 through an interfaceor port. Antenna 1111, interface 1114, and/or processing circuitry 1120may be configured to perform any receiving or transmitting operationsdescribed herein as being performed by a WD. Any information, dataand/or signals may be received from a network node and/or another WD. Insome embodiments, radio front end circuitry and/or antenna 1111 may beconsidered an interface.

As illustrated, interface 1114 comprises radio front end circuitry 1112and antenna 1111. Radio front end circuitry 1112 comprise one or morefilters 1118 and amplifiers 1116. Radio front end circuitry 1112 isconnected to antenna 1111 and processing circuitry 1120, and isconfigured to condition signals communicated between antenna 1111 andprocessing circuitry 1120. Radio front end circuitry 1112 may be coupledto or a part of antenna 1111. In some embodiments, WD 1110 may notinclude separate radio front end circuitry 1112; rather, processingcircuitry 1120 may comprise radio front end circuitry and may beconnected to antenna 1111. Similarly, in some embodiments, some or allof RF transceiver circuitry 1122 may be considered a part of interface1114. Radio front end circuitry 1112 may receive digital data that is tobe sent out to other network nodes or WDs via a wireless connection.Radio front end circuitry 1112 may convert the digital data into a radiosignal having the appropriate channel and bandwidth parameters using acombination of filters 1118 and/or amplifiers 1116. The radio signal maythen be transmitted via antenna 1111. Similarly, when receiving data,antenna 1111 may collect radio signals which are then converted intodigital data by radio front end circuitry 1112. The digital data may bepassed to processing circuitry 1120. In other embodiments, the interfacemay comprise different components and/or different combinations ofcomponents.

Processing circuitry 1120 may comprise a combination of one or more of amicroprocessor, controller, microcontroller, central processing unit,digital signal processor, application-specific integrated circuit, fieldprogrammable gate array, or any other suitable computing device,resource, or combination of hardware, software, and/or encoded logicoperable to provide, either alone or in conjunction with other WD 1110components, such as device readable medium 1130, WD 1110 functionality.Such functionality may include providing any of the various wirelessfeatures or benefits discussed herein. For example, processing circuitry1120 may execute instructions stored in device readable medium 1130 orin memory within processing circuitry 1120 to provide the functionalitydisclosed herein.

As illustrated, processing circuitry 1120 includes one or more of RFtransceiver circuitry 1122, baseband processing circuitry 1124, andapplication processing circuitry 1126. In other embodiments, theprocessing circuitry may comprise different components and/or differentcombinations of components. In certain embodiments processing circuitry1120 of WD 1110 may comprise a SOC. In some embodiments, RF transceivercircuitry 1122, baseband processing circuitry 1124, and applicationprocessing circuitry 1126 may be on separate chips or sets of chips. Inalternative embodiments, part or all of baseband processing circuitry1124 and application processing circuitry 1126 may be combined into onechip or set of chips, and RF transceiver circuitry 1122 may be on aseparate chip or set of chips. In still alternative embodiments, part orall of RF transceiver circuitry 1122 and baseband processing circuitry1124 may be on the same chip or set of chips, and application processingcircuitry 1126 may be on a separate chip or set of chips. In yet otheralternative embodiments, part or all of RF transceiver circuitry 1122,baseband processing circuitry 1124, and application processing circuitry1126 may be combined in the same chip or set of chips. In someembodiments, RF transceiver circuitry 1122 may be a part of interface1114. RF transceiver circuitry 1122 may condition RF signals forprocessing circuitry 1120.

In certain embodiments, some or all of the functionality describedherein as being performed by a WD may be provided by processingcircuitry 1120 executing instructions stored on device readable medium1130, which in certain embodiments may be a computer-readable storagemedium. In alternative embodiments, some or all of the functionality maybe provided by processing circuitry 1120 without executing instructionsstored on a separate or discrete device readable storage medium, such asin a hard-wired manner. In any of those particular embodiments, whetherexecuting instructions stored on a device readable storage medium ornot, processing circuitry 1120 can be configured to perform thedescribed functionality. The benefits provided by such functionality arenot limited to processing circuitry 1120 alone or to other components ofWD 1110, but are enjoyed by WD 1110 as a whole, and/or by end users andthe wireless network generally.

Processing circuitry 1120 may be configured to perform any determining,calculating, or similar operations (e.g., certain obtaining operations)described herein as being performed by a WD. These operations, asperformed by processing circuitry 1120, may include processinginformation obtained by processing circuitry 1120 by, for example,converting the obtained information into other information, comparingthe obtained information or converted information to information storedby WD 1110, and/or performing one or more operations based on theobtained information or converted information, and as a result of saidprocessing making a determination.

Device readable medium 1130 may be operable to store a computer program,software, an application including one or more of logic, rules, code,tables, etc. and/or other instructions capable of being executed byprocessing circuitry 1120. Device readable medium 1130 may includecomputer memory (e.g., Random Access Memory (RAM) or Read Only Memory(ROM)), mass storage media (e.g., a hard disk), removable storage media(e.g., a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or anyother volatile or non-volatile, non-transitory device readable and/orcomputer executable memory devices that store information, data, and/orinstructions that may be used by processing circuitry 1120. In someembodiments, processing circuitry 1120 and device readable medium 1130may be considered to be integrated.

User interface equipment 1132 may provide components that allow for ahuman user to interact with WD 1110. Such interaction may be of manyforms, such as visual, audial, tactile, etc. User interface equipment1132 may be operable to produce output to the user and to allow the userto provide input to WD 1110. The type of interaction may vary dependingon the type of user interface equipment 1132 installed in WD 1110. Forexample, if WD 1110 is a smart phone, the interaction may be via a touchscreen; if WD 1110 is a smart meter, the interaction may be through ascreen that provides usage (e.g., the number of gallons used) or aspeaker that provides an audible alert (e.g., if smoke is detected).User interface equipment 1132 may include input interfaces, devices andcircuits, and output interfaces, devices and circuits. User interfaceequipment 1132 is configured to allow input of information into WD 1110,and is connected to processing circuitry 1120 to allow processingcircuitry 1120 to process the input information. User interfaceequipment 1132 may include, for example, a microphone, a proximitysensor or other sensor, keys/buttons, a touch display, one or morecameras, a USB port, or other input circuitry. User interface equipment1132 is also configured to allow output of information from WD 1110, andto allow processing circuitry 1120 to output information from WD 1110.User interface equipment 1132 may include, for example, a speaker, adisplay, vibrating circuitry, a USB port, a headphone interface, orother output circuitry. Using one or more input and output interfaces,devices, and circuits, of user interface equipment 1132, WD 1110 maycommunicate with end users and/or the wireless network, and allow themto benefit from the functionality described herein.

Auxiliary equipment 1134 is operable to provide more specificfunctionality which may not be generally performed by WDs. This maycomprise specialized sensors for doing measurements for variouspurposes, interfaces for additional types of communication such as wiredcommunications etc. The inclusion and type of components of auxiliaryequipment 1134 may vary depending on the embodiment and/or scenario.

Power source 1136 may, in some embodiments, be in the form of a batteryor battery pack. Other types of power sources, such as an external powersource (e.g., an electricity outlet), photovoltaic devices or powercells, may also be used. WD 1110 may further comprise power circuitry1137 for delivering power from power source 1136 to the various parts ofWD 1110 which need power from power source 1136 to carry out anyfunctionality described or indicated herein. Power circuitry 1137 may incertain embodiments comprise power management circuitry. Power circuitry1137 may additionally or alternatively be operable to receive power froman external power source; in which case WD 1110 may be connectable tothe external power source (such as an electricity outlet) via inputcircuitry or an interface such as an electrical power cable. Powercircuitry 1137 may also in certain embodiments be operable to deliverpower from an external power source to power source 1136. This may be,for example, for the charging of power source 1136. Power circuitry 1137may perform any formatting, converting, or other modification to thepower from power source 1136 to make the power suitable for therespective components of WD 1110 to which power is supplied.

FIG. 16 illustrates one embodiment of a UE in accordance with variousaspects described herein. As used herein, a user equipment or UE may notnecessarily have a user in the sense of a human user who owns and/oroperates the relevant device. Instead, a UE may represent a device thatis intended for sale to, or operation by, a human user but which maynot, or which may not initially, be associated with a specific humanuser (e.g., a smart sprinkler controller). Alternatively, a UE mayrepresent a device that is not intended for sale to, or operation by, anend user but which may be associated with or operated for the benefit ofa user (e.g., a smart power meter). UE 1200 may be any UE identified bythe 3rd Generation Partnership Project (3GPP), including a NB-IoT UE, amachine type communication (MTC) UE, and/or an enhanced MTC (eMTC) UE.UE 1200, as illustrated in FIG. 16 , is one example of a WD configuredfor communication in accordance with one or more communication standardspromulgated by the 3rd Generation Partnership Project (3GPP), such as3GPP's GSM, UMTS, LTE, and/or 5G standards. As mentioned previously, theterm WD and UE may be used interchangeably. Accordingly, although FIG.16 is a UE, the components discussed herein are equally applicable to aWD, and vice-versa.

In FIG. 16 , UE 1200 includes processing circuitry 1201 that isoperatively coupled to input/output interface 1205, radio frequency (RF)interface 1209, network connection interface 1211, memory 1215 includingrandom access memory (RAM) 1217, read-only memory (ROM) 1219, andstorage medium 1221 or the like, communication subsystem 1231,transmitter 1233, and/or any other component, or any combinationthereof. Storage medium 1221 includes operating system 1223, applicationprogram 1225, and data 1227. In other embodiments, storage medium 1221may include other similar types of information. Certain UEs may utilizeall of the components shown in FIG. 16 , or only a subset of thecomponents. The level of integration between the components may varyfrom one UE to another UE. Further, certain UEs may contain multipleinstances of a component, such as multiple processors, memories,transceivers, transmitters, receivers, etc.

In FIG. 16 , processing circuitry 1201 may be configured to processcomputer instructions and data. Processing circuitry 1201 may beconfigured to implement any sequential state machine operative toexecute machine instructions stored as machine-readable computerprograms in the memory, such as one or more hardware-implemented statemachines (e.g., in discrete logic, FPGA, ASIC, etc.); programmable logictogether with appropriate firmware; one or more stored program,general-purpose processors, such as a microprocessor or Digital SignalProcessor (DSP), together with appropriate software; or any combinationof the above. For example, the processing circuitry 1201 may include twocentral processing units (CPUs). Data may be information in a formsuitable for use by a computer.

In the depicted embodiment, input/output interface 1205 may beconfigured to provide a communication interface to an input device,output device, or input and output device. UE 1200 may be configured touse an output device via input/output interface 1205. An output devicemay use the same type of interface port as an input device. For example,a USB port may be used to provide input to and output from UE 1200. Theoutput device may be a speaker, a sound card, a video card, a display, amonitor, a printer, an actuator, an emitter, a smartcard, another outputdevice, or any combination thereof. UE 1200 may be configured to use aninput device via input/output interface 1205 to allow a user to captureinformation into UE 1200. The input device may include a touch-sensitiveor presence-sensitive display, a camera (e.g., a digital camera, adigital video camera, a web camera, etc.), a microphone, a sensor, amouse, a trackball, a directional pad, a trackpad, a scroll wheel, asmartcard, and the like. The presence-sensitive display may include acapacitive or resistive touch sensor to sense input from a user. Asensor may be, for instance, an accelerometer, a gyroscope, a tiltsensor, a force sensor, a magnetometer, an optical sensor, a proximitysensor, another like sensor, or any combination thereof. For example,the input device may be an accelerometer, a magnetometer, a digitalcamera, a microphone, and an optical sensor.

In FIG. 16 , RF interface 1209 may be configured to provide acommunication interface to RF components such as a transmitter, areceiver, and an antenna. Network connection interface 1211 may beconfigured to provide a communication interface to network 1243 a.Network 1243 a may encompass wired and/or wireless networks such as alocal-area network (LAN), a wide-area network (WAN), a computer network,a wireless network, a telecommunications network, another like networkor any combination thereof. For example, network 1243 a may comprise aWi-Fi network. Network connection interface 1211 may be configured toinclude a receiver and a transmitter interface used to communicate withone or more other devices over a communication network according to oneor more communication protocols, such as Ethernet, TCP/IP, SONET, ATM,or the like. Network connection interface 1211 may implement receiverand transmitter functionality appropriate to the communication networklinks (e.g., optical, electrical, and the like). The transmitter andreceiver functions may share circuit components, software or firmware,or alternatively may be implemented separately.

RAM 1217 may be configured to interface via bus 1202 to processingcircuitry 1201 to provide storage or caching of data or computerinstructions during the execution of software programs such as theoperating system, application programs, and device drivers. ROM 1219 maybe configured to provide computer instructions or data to processingcircuitry 1201. For example, ROM 1219 may be configured to storeinvariant low-level system code or data for basic system functions suchas basic input and output (I/O), startup, or reception of keystrokesfrom a keyboard that are stored in a non-volatile memory. Storage medium1221 may be configured to include memory such as RAM, ROM, programmableread-only memory (PROM), erasable programmable read-only memory (EPROM),electrically erasable programmable read-only memory (EEPROM), magneticdisks, optical disks, floppy disks, hard disks, removable cartridges, orflash drives. In one example, storage medium 1221 may be configured toinclude operating system 1223, application program 1225 such as a webbrowser application, a widget or gadget engine or another application,and data 1227. Storage medium 1221 may store, for use by UE 1200, any ofa variety of various operating systems or combinations of operatingsystems.

Storage medium 1221 may be configured to include a number of physicaldrive units, such as redundant array of independent disks (RAID), floppydisk drive, flash memory, USB flash drive, external hard disk drive,thumb drive, pen drive, key drive, high-density digital versatile disc(HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray opticaldisc drive, holographic digital data storage (HDDS) optical disc drive,external mini-dual in-line memory module (DIMM), synchronous dynamicrandom access memory (SDRAM), external micro-DIMM SDRAM, smartcardmemory such as a subscriber identity module or a removable user identitymodule (SIM/RUIM), other memory, or any combination thereof. Storagemedium 1221 may allow UE 1200 to access computer-executableinstructions, application programs or the like, stored on transitory ornon-transitory memory media, to off-load data, or to upload data. Anarticle of manufacture, such as one utilizing a communication system maybe tangibly embodied in storage medium 1221, which may comprise a devicereadable medium.

In FIG. 16 , processing circuitry 1201 may be configured to communicatewith network 1243 b using communication subsystem 1231. Network 1243 aand network 1243 b may be the same network or networks or differentnetwork or networks. Communication subsystem 1231 may be configured toinclude one or more transceivers used to communicate with network 1243b. For example, communication subsystem 1231 may be configured toinclude one or more transceivers used to communicate with one or moreremote transceivers of another device capable of wireless communicationsuch as another WD, UE, or base station of a radio access network (RAN)according to one or more communication protocols, such as IEEE 802.12,CDMA, WCDMA, GSM, LTE, UTRAN, WiMax, or the like. Each transceiver mayinclude transmitter 1233 and/or receiver 1235 to implement transmitteror receiver functionality, respectively, appropriate to the RAN links(e.g., frequency allocations and the like). Further, transmitter 1233and receiver 1235 of each transceiver may share circuit components,software or firmware, or alternatively may be implemented separately.

In the illustrated embodiment, the communication functions ofcommunication subsystem 1231 may include data communication, voicecommunication, multimedia communication, short-range communications suchas Bluetooth, near-field communication, location-based communicationsuch as the use of the global positioning system (GPS) to determine alocation, another like communication function, or any combinationthereof. For example, communication subsystem 1231 may include cellularcommunication, Wi-Fi communication, Bluetooth communication, and GPScommunication. Network 1243 b may encompass wired and/or wirelessnetworks such as a local-area network (LAN), a wide-area network (WAN),a computer network, a wireless network, a telecommunications network,another like network or any combination thereof. For example, network1243 b may be a cellular network, a Wi-Fi network, and/or a near-fieldnetwork. Power source 1213 may be configured to provide alternatingcurrent (AC) or direct current (DC) power to components of UE 1200.

The features, benefits and/or functions described herein may beimplemented in one of the components of UE 1200 or partitioned acrossmultiple components of UE 1200. Further, the features, benefits, and/orfunctions described herein may be implemented in any combination ofhardware, software or firmware. In one example, communication subsystem1231 may be configured to include any of the components describedherein. Further, processing circuitry 1201 may be configured tocommunicate with any of such components over bus 1202. In anotherexample, any of such components may be represented by programinstructions stored in memory that when executed by processing circuitry1201 perform the corresponding functions described herein. In anotherexample, the functionality of any of such components may be partitionedbetween processing circuitry 1201 and communication subsystem 1231. Inanother example, the non-computationally intensive functions of any ofsuch components may be implemented in software or firmware and thecomputationally intensive functions may be implemented in hardware.

FIG. 17 is a schematic block diagram illustrating a virtualizationenvironment 1300 in which functions implemented by some embodiments maybe virtualized. In the present context, virtualizing means creatingvirtual versions of apparatuses or devices which may includevirtualizing hardware platforms, storage devices and networkingresources. As used herein, virtualization can be applied to a node(e.g., a virtualized base station or a virtualized radio access node) orto a device (e.g., a UE, a wireless device or any other type ofcommunication device) or components thereof and relates to animplementation in which at least a portion of the functionality isimplemented as one or more virtual components (e.g., via one or moreapplications, components, functions, virtual machines or containersexecuting on one or more physical processing nodes in one or morenetworks).

In some embodiments, some or all of the functions described herein maybe implemented as virtual components executed by one or more virtualmachines implemented in one or more virtual environments 1300 hosted byone or more of hardware nodes 1330. Further, in embodiments in which thevirtual node is not a radio access node or does not require radioconnectivity (e.g., a core network node), then the network node may beentirely virtualized.

The functions may be implemented by one or more applications 1320 (whichmay alternatively be called software instances, virtual appliances,network functions, virtual nodes, virtual network functions, etc.)operative to implement some of the features, functions, and/or benefitsof some of the embodiments disclosed herein. Applications 1320 are runin virtualization environment 1300 which provides hardware 1330comprising processing circuitry 1360 and memory 1390-1. Memory 1390-1contains instructions 1395 executable by processing circuitry 1360whereby application 1320 is operative to provide one or more of thefeatures, benefits, and/or functions disclosed herein.

Virtualization environment 1300, comprises general-purpose orspecial-purpose network hardware devices 1330 comprising a set of one ormore processors or processing circuitry 1360, which may be commercialoff-the-shelf (COTS) processors, dedicated Application SpecificIntegrated Circuits (ASICs), or any other type of processing circuitryincluding digital or analog hardware components or special purposeprocessors. Each hardware device may comprise memory 1390-1 which may benon-persistent memory for temporarily storing instructions 1395 orsoftware executed by processing circuitry 1360. Each hardware device maycomprise one or more network interface controllers (NICs) 1370, alsoknown as network interface cards, which include physical networkinterface 1380. Each hardware device may also include non-transitory,persistent, machine-readable storage media 1390-2 having stored thereinsoftware 1395 and/or instructions executable by processing circuitry1360. Software 1395 may include any type of software including softwarefor instantiating one or more virtualization layers 1350 (also referredto as hypervisors), software to execute virtual machines 1340 as well assoftware allowing it to execute functions, features and/or benefitsdescribed in relation with some embodiments described herein.

Virtual machines 1340, comprise virtual processing, virtual memory,virtual networking or interface and virtual storage, and may be run by acorresponding virtualization layer 1350 or hypervisor. Differentembodiments of the instance of virtual appliance 1320 may be implementedon one or more of virtual machines 1340, and the implementations may bemade in different ways.

During operation, processing circuitry 1360 executes software 1395 toinstantiate the hypervisor or virtualization layer 1350, which maysometimes be referred to as a virtual machine monitor (VMM).Virtualization layer 1350 may present a virtual operating platform thatappears like networking hardware to virtual machine 1340.

As shown in FIG. 16 , hardware 1330 may be a standalone network nodewith generic or specific components. Hardware 1330 may comprise antenna13225 and may implement some functions via virtualization.Alternatively, hardware 1330 may be part of a larger cluster of hardware(e.g., such as in a data center or customer premise equipment (CPE))where many hardware nodes work together and are managed via managementand orchestration (MANO) 13100, which, among others, oversees lifecyclemanagement of applications 1320.

Virtualization of the hardware is in some contexts referred to asnetwork function virtualization (NFV). NFV may be used to consolidatemany network equipment types onto industry standard high volume serverhardware, physical switches, and physical storage, which can be locatedin data centers, and customer premise equipment.

In the context of NFV, virtual machine 1340 may be a softwareimplementation of a physical machine that runs programs as if they wereexecuting on a physical, non-virtualized machine. Each of virtualmachines 1340, and that part of hardware 1330 that executes that virtualmachine, be it hardware dedicated to that virtual machine and/orhardware shared by that virtual machine with others of the virtualmachines 1340, forms a separate virtual network elements (VNE).

Still in the context of NFV, Virtual Network Function (VNF) isresponsible for handling specific network functions that run in one ormore virtual machines 1340 on top of hardware networking infrastructure1330 and corresponds to application 1320 in FIG. 16 .

In some embodiments, one or more radio units 13200 that each include oneor more transmitters 13220 and one or more receivers 13210 may becoupled to one or more antennas 13225. Radio units 13200 may communicatedirectly with hardware nodes 1330 via one or more appropriate networkinterfaces and may be used in combination with the virtual components toprovide a virtual node with radio capabilities, such as a radio accessnode or a base station.

In some embodiments, some signaling can be effected with the use ofcontrol system 13230 which may alternatively be used for communicationbetween the hardware nodes 1330 and radio units 13200.

FIG. 18 illustrates a telecommunication network connected via anintermediate network to a host computer in accordance with someembodiments. In particular, with reference to FIG. 18 , in accordancewith an embodiment, a communication system includes telecommunicationnetwork 1410, such as a 3GPP-type cellular network, which comprisesaccess network 1411, such as a radio access network, and core network1414. Access network 1411 comprises a plurality of base stations 1412 a,1412 b, 1412 c, such as NBs, eNBs, gNBs or other types of wirelessaccess points, each defining a corresponding coverage area 1413 a, 1413b, 1413 c. Each base station 1412 a, 1412 b, 1412 c is connectable tocore network 1414 over a wired or wireless connection 1415. A first UE1491 located in coverage area 1413 c is configured to wirelessly connectto, or be paged by, the corresponding base station 1412 c. A second UE1492 in coverage area 1413 a is wirelessly connectable to thecorresponding base station 1412 a. While a plurality of UEs 1491, 1492are illustrated in this example, the disclosed embodiments are equallyapplicable to a situation where a sole UE is in the coverage area orwhere a sole UE is connecting to the corresponding base station 1412.

Telecommunication network 1410 is itself connected to host computer1430, which may be embodied in the hardware and/or software of astandalone server, a cloud-implemented server, and a distributed serveror as processing resources in a server farm. Host computer 1430 may beunder the ownership or control of a service provider, or may be operatedby the service provider or on behalf of the service provider.Connections 1421 and 1422 between telecommunication network 1410 andhost computer 1430 may extend directly from core network 1414 to hostcomputer 1430 or may go via an optional intermediate network 1420.Intermediate network 1420 may be one of, or a combination of more thanone of, a public, private or hosted network; intermediate network 1420,if any, may be a backbone network or the Internet; in particular,intermediate network 1420 may comprise two or more sub-networks (notshown).

The communication system of FIG. 18 as a whole enables connectivitybetween the connected UEs 1491, 1492 and host computer 1430. Theconnectivity may be described as an over-the-top (OTT) connection 1450.Host computer 1430 and the connected UEs 1491, 1492 are configured tocommunicate data and/or signaling via OTT connection 1450, using accessnetwork 1411, core network 1414, any intermediate network 1420 andpossible further infrastructure (not shown) as intermediaries. OTTconnection 1450 may be transparent in the sense that the participatingcommunication devices through which OTT connection 1450 passes areunaware of routing of uplink and downlink communications. For example,base station 1412 may not or need not be informed about the past routingof an incoming downlink communication with data originating from hostcomputer 1430 to be forwarded (e.g., handed over) to a connected UE1491. Similarly, base station 1412 need not be aware of the futurerouting of an outgoing uplink communication originating from the UE 1491towards the host computer 1430.

Example implementations, in accordance with an embodiment, of the UE,base station and host computer discussed in the preceding paragraphswill now be described with reference to FIG. 19 . FIG. 19 illustrateshost computer communicating via a base station with a user equipmentover a partially wireless connection in accordance with some embodimentsin communication system 1500, host computer 1510 comprises hardware 1515including communication interface 1516 configured to set up and maintaina wired or wireless connection with an interface of a differentcommunication device of communication system 1500. Host computer 1510further comprises processing circuitry 1518, which may have storageand/or processing capabilities. In particular, processing circuitry 1518may comprise one or more programmable processors, application-specificintegrated circuits, field programmable gate arrays or combinations ofthese (not shown) adapted to execute instructions. Host computer 1510further comprises software 1511, which is stored in or accessible byhost computer 1510 and executable by processing circuitry 1518. Software1511 includes host application 1512. Host application 1512 may beoperable to provide a service to a remote user, such as UE 1530connecting via OTT connection 1550 terminating at UE 1530 and hostcomputer 1510. In providing the service to the remote user, hostapplication 1512 may provide user data which is transmitted using OTTconnection 1550.

Communication system 1500 further includes base station 1520 provided ina telecommunication system and comprising hardware 1525 enabling it tocommunicate with host computer 1510 and with UE 1530. Hardware 1525 mayinclude communication interface 1526 for setting up and maintaining awired or wireless connection with an interface of a differentcommunication device of communication system 1500, as well as radiointerface 1527 for setting up and maintaining at least wirelessconnection 1570 with UE 1530 located in a coverage area (not shown inFIG. 19 ) served by base station 1520. Communication interface 1526 maybe configured to facilitate connection 1560 to host computer 1510.Connection 1560 may be direct or it may pass through a core network (notshown in FIG. 19 ) of the telecommunication system and/or through one ormore intermediate networks outside the telecommunication system. In theembodiment shown, hardware 1525 of base station 1520 further includesprocessing circuitry 1528, which may comprise one or more programmableprocessors, application-specific integrated circuits, field programmablegate arrays or combinations of these (not shown) adapted to executeinstructions. Base station 1520 further has software 1521 storedinternally or accessible via an external connection.

Communication system 1500 further includes UE 1530 already referred to.Its hardware 1535 may include radio interface 1537 configured to set upand maintain wireless connection 1570 with a base station serving acoverage area in which UE 1530 is currently located. Hardware 1535 of UE1530 further includes processing circuitry 1538, which may comprise oneor more programmable processors, application-specific integratedcircuits, field programmable gate arrays or combinations of these (notshown) adapted to execute instructions. UE 1530 further comprisessoftware 1531, which is stored in or accessible by UE 1530 andexecutable by processing circuitry 1538. Software 1531 includes clientapplication 1532. Client application 1532 may be operable to provide aservice to a human or non-human user via UE 1530, with the support ofhost computer 1510. In host computer 1510, an executing host application1512 may communicate with the executing client application 1532 via OTTconnection 1550 terminating at UE 1530 and host computer 1510. Inproviding the service to the user, client application 1532 may receiverequest data from host application 1512 and provide user data inresponse to the request data. OTT connection 1550 may transfer both therequest data and the user data. Client application 1532 may interactwith the user to generate the user data that it provides.

It is noted that host computer 1510, base station 1520 and UE 1530illustrated in FIG. 19 may be similar or identical to host computer1430, one of base stations 1412 a, 1412 b, 1412 c and one of UEs 1491,1492 of FIG. 18 , respectively. This is to say, the inner workings ofthese entities may be as shown in FIG. 19 and independently, thesurrounding network topology may be that of FIG. 18 .

In FIG. 19 , OTT connection 1550 has been drawn abstractly to illustratethe communication between host computer 1510 and UE 1530 via basestation 1520, without explicit reference to any intermediary devices andthe precise routing of messages via these devices. Networkinfrastructure may determine the routing, which it may be configured tohide from UE 1530 or from the service provider operating host computer1510, or both. While OTT connection 1550 is active, the networkinfrastructure may further take decisions by which it dynamicallychanges the routing (e.g., on the basis of load balancing considerationor reconfiguration of the network).

Wireless connection 1570 between UE 1530 and base station 1520 is inaccordance with the teachings of the embodiments described throughoutthis disclosure. One or more of the various embodiments improve theperformance of OTT services provided to UE 1530 using OTT connection1550, in which wireless connection 1570 forms the last segment. Moreprecisely, the teachings of these embodiments may improve the continuityof service when performing an intra-RAT handover with a core networkchange and thereby provide benefits such as continuity of service andimproved customer experience.

A measurement procedure may be provided for the purpose of monitoringdata rate, latency and other factors on which the one or moreembodiments improve. There may further be an optional networkfunctionality for reconfiguring OTT connection 1550 between hostcomputer 1510 and UE 1530, in response to variations in the measurementresults. The measurement procedure and/or the network functionality forreconfiguring OTT connection 1550 may be implemented in software 1511and hardware 1515 of host computer 1510 or in software 1531 and hardware1535 of UE 1530, or both. In embodiments, sensors (not shown) may bedeployed in or in association with communication devices through whichOTT connection 1550 passes; the sensors may participate in themeasurement procedure by supplying values of the monitored quantitiesexemplified above, or supplying values of other physical quantities fromwhich software 1511, 1531 may compute or estimate the monitoredquantities. The reconfiguring of OTT connection 1550 may include messageformat, retransmission settings, preferred routing etc. Thereconfiguring need not affect base station 1520, and it may be unknownor imperceptible to base station 1520. Such procedures andfunctionalities may be known and practiced in the art. In certainembodiments, measurements may involve proprietary UE signalingfacilitating host computer 1510 measurements of throughput, propagationtimes, latency and the like. The measurements may be implemented in thatsoftware 1511 and 1531 causes messages to be transmitted, in particularempty or ‘dummy’ messages, using OTT connection 1550 while it monitorspropagation times, errors etc.

FIG. 20 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIGS. 18 and 19 . Forsimplicity of the present disclosure, only drawing references to FIG. 20will be included in this section. In step 1610, the host computerprovides user data. In substep 1611 (which may be optional) of step1610, the host computer provides the user data by executing a hostapplication. In step 1620, the host computer initiates a transmissioncarrying the user data to the UE. In step 1630 (which may be optional),the base station transmits to the UE the user data which was carried inthe transmission that the host computer initiated, in accordance withthe teachings of the embodiments described throughout this disclosure.In step 1640 (which may also be optional), the UE executes a clientapplication associated with the host application executed by the hostcomputer.

FIG. 21 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIGS. 18 and 19 . Forsimplicity of the present disclosure, only drawing references to FIG. 21will be included in this section. In step 1710 of the method, the hostcomputer provides user data. In an optional substep (not shown) the hostcomputer provides the user data by executing a host application. In step1720, the host computer initiates a transmission carrying the user datato the UE. The transmission may pass via the base station, in accordancewith the teachings of the embodiments described throughout thisdisclosure. In step 1730 (which may be optional), the UE receives theuser data carried in the transmission.

FIG. 22 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIGS. 18 and 19 . Forsimplicity of the present disclosure, only drawing references to FIG. 22will be included in this section. In step 1810 (which may be optional),the UE receives input data provided by the host computer. Additionallyor alternatively, in step 1820, the UE provides user data. In substep1821 (which may be optional) of step 1820, the UE provides the user databy executing a client application. In substep 1811 (which may beoptional) of step 1810, the UE executes a client application whichprovides the user data in reaction to the received input data providedby the host computer. In providing the user data, the executed clientapplication may further consider user input received from the user.Regardless of the specific manner in which the user data was provided,the UE initiates, in step 1830 (which may be optional), transmission ofthe user data to the host computer. In step 1840 of the method, the hostcomputer receives the user data transmitted from the UE, in accordancewith the teachings of the embodiments described throughout thisdisclosure.

FIG. 23 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIGS. 18 and 19 . Forsimplicity of the present disclosure, only drawing references to FIG. 23will be included in this section. In step 1910 (which may be optional),in accordance with the teachings of the embodiments described throughoutthis disclosure, the base station receives user data from the UE. Instep 1920 (which may be optional), the base station initiatestransmission of the received user data to the host computer. In step1930 (which may be optional), the host computer receives the user datacarried in the transmission initiated by the base station.

Any appropriate steps, methods, features, functions, or benefitsdisclosed herein may be performed through one or more functional unitsor modules of one or more virtual apparatuses. Each virtual apparatusmay comprise a number of these functional units. These functional unitsmay be implemented via processing circuitry, which may include one ormore microprocessors or microcontrollers, as well as other digitalhardware, which may include digital signal processors (DSPs),special-purpose digital logic, and the like. The processing circuitrymay be configured to execute program code stored in memory, which mayinclude one or several types of memory such as read-only memory (ROM),random-access memory (RAM), cache memory, flash memory devices, opticalstorage devices, etc. Program code stored in memory includes programinstructions for executing one or more telecommunications and/or datacommunications protocols as well as instructions for carrying out one ormore of the techniques described herein. In some implementations, theprocessing circuitry may be used to cause the respective functional unitto perform corresponding functions according to one or more embodimentsof the present disclosure.

Generally, all terms used herein are to be interpreted according totheir ordinary meaning in the relevant technical field, unless adifferent meaning is clearly given and/or is implied from the context inwhich it is used. All references to a/an/the element, apparatus,component, means, step, etc. are to be interpreted openly as referringto at least one instance of the element, apparatus, component, means,step, etc., unless explicitly stated otherwise. The steps of any methodsdisclosed herein do not have to be performed in the exact orderdisclosed, unless a step is explicitly described as following orpreceding another step and/or where it is implicit that a step mustfollow or precede another step. Any feature of any of the embodimentsdisclosed herein may be applied to any other embodiment, whereverappropriate. Likewise, any advantage of any of the embodiments may applyto any other embodiments, and vice versa. Other objectives, features andadvantages of the enclosed embodiments will be apparent from thedescription.

The term unit may have conventional meaning in the field of electronics,electrical devices and/or electronic devices and may include, forexample, electrical and/or electronic circuitry, devices, modules,processors, memories, logic solid state and/or discrete devices,computer programs or instructions for carrying out respective tasks,procedures, computations, outputs, and/or displaying functions, and soon, as such as those that are described herein.

Some of the embodiments contemplated herein are described more fullywith reference to the accompanying drawings. Other embodiments, however,are contained within the scope of the subject matter disclosed herein.The disclosed subject matter should not be construed as limited to onlythe embodiments set forth herein; rather, these embodiments are providedby way of example to convey the scope of the subject matter to thoseskilled in the art.

What is claimed is:
 1. A method implemented by a user equipment in awireless communication network of performing a handover from a sourcenode connected to a first core network to a target node connected to asecond core network, said method comprising: receiving, from the sourcenode, a mobility command including an indication of a radio accesstechnology, RAT, used by the target node and a message containercontaining configuration information for the target node; determiningbased on the indication of the RAT used by the target node whether totreat the handover as an inter-RAT handover or as an intra-RAT handoverwith a core network change, wherein the determining comprisesdetermining to treat the handover as an intra-RAT handover with a corenetwork change when the indication indicates a first type of RAT; andperforming a radio resource control, RRC, procedure for an intra-RAThandover with a core network change based on the determination to treatthe handover as an intra-RAT handover with a core network change,wherein performing the RRC procedure for an intra-RAT handover with acore network change comprises inter-RAT handover signaling procedureand, upon successfully completing the handover, remaining in a RadioResource Control Connected, RRC_CONNECTED, state and ending the RRCprocedure.
 2. The method of claim 1, wherein the first type of RAT isEvolved Universal Mobile Telecommunications System, UMTS, TerrestrialRadio Access, E-UTRA.
 3. The method of claim 1, wherein performing aradio resource control procedure based on the determination comprises:upon occurrence of a mobility failure, performing an intra-RAT handoverfailure procedure.
 4. The method of claim 3, wherein the mobilityfailure comprises a reconfiguration failure, a handover to EUTRAfailure, or a timer expiration.
 5. The method of claim 1, wherein themobility command comprises an E-UTRA MobilityFromEUTRACommand.
 6. Themethod of claim 5, wherein the message container contains an E-UTRARRCConnectionReconfiguration message from the target node.
 7. The methodof claim 1, wherein the first core network comprises an Evolved PacketCore, EPC, network and the second core network comprise a 5th GenerationCore, 5GC, network.
 8. The method of claim 1, wherein the first corenetwork comprises a 5th Generation Core, 5GC, network and the secondcore network comprises an Evolved Packet Core, EPC, network.
 9. Anon-transitory computer-readable storage medium containing a computerprogram comprising executable instructions that, when executed by aprocessing circuit in a user equipment in a wireless communicationnetwork causes the user equipment to perform the method of claim
 1. 10.A user equipment in a wireless communication network, said userequipment being configured to: receive, from a source node, a mobilitycommand including an indication of a radio access technology, RAT, usedby a target node and a message container containing configurationinformation for the target node; determine, based on the indication ofthe RAT used by the target node, whether to treat a handover of the userequipment as an inter-RAT handover or as an intra-RAT handover with acore network change, wherein when the indication indicates a first typeof RAT, treat the handover as an intra-RAT handover with a core networkchange; and perform a radio resource control, RRC, procedure for anintra-RAT handover with a core network change based on the determinationto treat the handover as an intra-RAT handover with a core networkchange, wherein performing the RRC procedure for an intra-RAT handoverwith a core network change comprises inter-RAT handover signalingprocedure and, upon successfully completing the handover, remaining in aRadio Resource Control Connected, RRC_CONNECTED, state and ending theRRC procedure.
 11. The user equipment of claim 10, wherein the firsttype of RAT is Evolved Universal Mobile Telecommunications System, UMTS,Terrestrial Radio Access, EUTRA.
 12. The user equipment of claim 11,wherein the processing circuit is further configured to, upon occurrenceof a mobility failure, perform an intra-RAT handover failure procedure.13. The user equipment of claim 12, wherein the mobility failurecomprises a reconfiguration failure or a handover to E-UTRA failure. 14.The user equipment of claim 10, wherein the mobility command comprisesan E-UTRA MobilityFromEUTRACommand.
 15. The user equipment of claim 14,wherein the message container contains an E-UTRARRCConnectionReconfiguration message from the target node.
 16. The userequipment of claim 10, wherein the core network comprises an EvolvedPacket Core, EPC, network or a 5th Generation Core, 5GC, network.